The Raspberry Pi Foundation has released a new version of the Raspbian GNU/Linux operating system, based on the latest Debian GNU/Linux (Stretch), for all models of Raspberry Pi and for PC and Mac systems.
The release announcement makes clear that this is mostly bug fixes and minor tweaks, but there are a few changes which are intended to make using Raspbian a bit easier to use, or to make the desktop GUI a bit cleaner. There is also a very brief mention of a couple of new features in the PC version which appear to be intended to make it easier to manage and use a group of Raspberry Pi systems from a Raspbian PC or Mac server.
There is not much information about these features yet, but more is promised for the near future: this could be particularly interesting for educational or lab environments.
By the way, if you read the release announcement, you need to be careful about some confusing terminology used there. The PC release is sometimes referred to as a 'Windows' release, which apparently gave some users hope that it was some kind of hosted version which would run under Windows (thankfully, it is not), and the PC/Mac releases are also sometimes referred to as the 'Debian version'. I think what they are getting at with this is the the PC/Mac versions are not really Raspbian, they want them to be called 'Debian with Raspberry Pi Desktop'. But it is still pretty inconsistent at this point, and it gets a bit messy and confusing, so be aware.
If you already have a running Raspberry Pi system, you don't need to reinstall to get this update. All you need to do is the usual:
Depending on what Pi model you have and how long it has been since you last updated, this will take between five and 30 minutes. That last bit, autoremove, is not really necessary to get the update installed, but it helps to clean out old, outdated, or unused packages and thus helps to keep your disk from filling up too fast.
Reboot after the update has finished, and you should be running Linux kernel 4.9.59 (or later). You will also get a notification window like this:
This confirms for you that the installation was installed, and if you happen to have modified any of the configuration files, reminds you that you should go and check them against the new versions to see if your modifications are still necessary.
The only significant change in the user interface that you are likely to notice is a simplification of the file manager utility PCManFM. I think this is a real improvement, but if you prefer the original version (a bit masochistic, perhaps?), you can change a setting in the Edit/Preferences/Layout dialog, and get it back.
I have upgraded the existing installations on at least one of each Pi model I have (Zero, B, B+, 2 and 3), and I haven't had any trouble at all. If you want to be reminded of how slow an original Pi Model B is, try installing this update on one immediately after you have installed it on a Pi 3.
I have also made one new installation on a Pi 3 (the microSD card seemed to be missing from that one, strange), and that also went without trouble.
Moving on to the PC/Mac version, my advice about installation is different than for the Pi version.
Because that version had not yet been updated from Debian Jessie to Stretch, there is a lot more to be done if you want to update a running system. Unless you have some very good reason to update in place rather than making a new installation, I would advise you not to slog through the update process (the necessary commands are documented in the release announcement). Just download the new ISO image from the PC and Mac Downloads page, and copy that to a USB stick with something like this:
In fact, after having had Raspbian PIXEL installed on one of my laptops for a while, I would even make make my advice a bit stronger. If you don't have a good reason to install it to the hard drive (ie if you don't plan on using it very often at this time), I would recommend just running it from the USB stick when you want or need it.
The boot menu gives you the option of booting with or without persistence; if you choose to have persistence, then files you create in your home directory will be preserved across boots, rather than starting from an absolute clean system every time you boot it.
Also, if you choose to boot with persistence, you still have the option on boot to clear any existing files and data, and boot once again from a clean image but still with persistence enabled (basically a 'persistence reset'). This is really one of the best and most flexible boot configurations I have seen for a Live USB image.
The only disadvantage I can see to running from the USB stick rather than installing to disk is that you will have to use whatever the boot-select option is for your system whenever you want to run it. I can think of a couple of advantages: first, the PC/Mac version is still very much in development, so there are likely to be more of this kind of major update coming in the future, and second you don't have to go through the installation procedure and take the risk that you end up doing something to your computer that you didn't really mean to -- like wipe out everything else on the disk.
The screenshot below shows the PC version running on my Acer Aspire V laptop, from the USB stick.
Here you can see the other significant change to the PIXEL desktop: a battery indicator has been added to the task bar.
Finally, I would like to add a comment about browsers on Raspbian. The standard browser included with Raspbian has been Chromium for some time now. Setting aside the fact that I really don't like Chromium (or Chrome), I find it to be generally too slow on the Raspberry Pi for my taste. On a Pi 3 it is just irritatingly slow to start up, then I guess it is more or less OK. But on any other model it is just painfully slow, and in the worst case, running on an original Pi Model B or B+, waiting for it to start up reminds you of your mortality. I have this mental image of my dessicated corpse sitting in front of a Pi ModelB system, still waiting for Chromium to start...
Rather than wait on Chromium, I always simply install the Midori browser as part of the initial setup on any Raspberry Pi (including the Pi 3). It is easy to install:
sudo apt-get install midori
The only small trick is getting it on the panel instead of Chromium. You can do this by right-clicking on the Launch Bar at the left end of the panel and choosing 'Application Launch Bar Settings'. Then delete the existing web browser, and add Midori from the 'Internet' category.
I think it might be possible to just make Midori the default browser, and then the original 'Web Browser' launcher would start Midori rather than Chromium. But I can't see how to make that change right now -- if anyone knows, feel free to add a comment. Anyway, replacing the launcher as described above has the additional benefit that you get a nice Midori icon in the panel, rather than the generic web browser icon.