Of course, I went straight to the good folks at the Swiss Pi-Shop.ch and ordered one, which I received the next day.
So, the first thing on my to-do list is to congratulate and thank both the Pi Foundation and the Pi-Shop.ch for their efficiency in making this new model available immediately after announcement.
The official announcement on the Raspberry Pi Blog gives all the details. There is a cute little video which highlights the improvements, and then a longer blog post which fills in the details. In a nutshell, it comes down to this:
The CPU speed has been bumped up to 1.4GHz
The Wi-Fi has been bumped up to 802.11ac
The Bluetooth has been bumped up to 4.2
The Wired Ethernet connection has been bumped up to 1Gbps (but see below for a caveat on this)
Power-over-Ethernet capability has been added (but see below for a caveat on this)
Network and USB boot have been improved
Thermal management has been improved (so the higher CPU speed doesn't turn your Pi3B+ into a pile of goo)
None of that is earth-shattering, which probably goes a long way toward explaining why this is not called the Raspberry Pi 4, but it all adds up to a very nicely improved Raspberry Pi 3.
OK, let's start with the caveats. First, the Gigabit ethernet still connects to the CPU via the USB 2.0 bus, which means that it actually has a maximum speed of about 300Mpbs. That is still about a three-fold improvement over the 100Mbps wired ethernet in all previous Raspberry Pi models (including the Pi 3 Model B). Actually a bit more than three-fold, since the original didn't quite get the full 100Mbps, and the 3B+ gets slightly more than 300Mbps.
Second, although PoE (Power-over-Ethernet) capability has been added, the actual hardware to accomplish this is not included in the base configuration. There will be a PoE HAT (add-on board) available soon, which will connect to a new four-pin header that was added for this purpose.
I will add a caveat to the caveat about this: the four-pin header is new. As you can see in the picture, it sticks up from the motherboard. There was nothing sticking up in this location on any previous Raspberry Pi model. Some Pi cases are shaped and molded in such a way that they won't fit the 3B+ because of this new header.
I have tried the official Raspberry Pi case, and it fits just fine in that. But if you are ordering any other case, make sure that you check that it is compatible with the 3B+. Here are a couple of other examples, which I have written about previously, and which I have tried:
The wireless networking improvements have come about thanks to a new 'combo' Wi-Fi and Bluetooth chip, which has a rather spiffy embossed metal shield. The shield is not just for looks, though, because it has made it possible for them to get FCC radio certification for the board, which could make life a lot easier for those who want to make other products using the 3B+.
If you only have 2.4GHz Wi-Fi, you will see only a small improvement in wireless networking performance. But of you have 5GHz Wi-Fi available, you could see as much as a three-fold improvement in wireless performance. Zowie, that's good stuff!
Oh, and one other piece of wireless good news, I found that my Bluetooth mouse connects to the 3B+ without the silly "connected, but no services available" message. Not a big deal, I know, but at least it's one fewer small irritant.
OK, so much for hardware, now what about software? Well, as has pretty much always been the case, the Pi Foundation has put a lot of effort into making sure that the new hardware is as compatible as possible with previous models.
There is a new release of Raspbian to support the 3B+, which you can get from the Pi Downloads page, or you can install the latest updates on an existing Raspbian image. Note that if you are running Raspbian already, and you haven't updated it for a while, that SD card will probably not boot in the Pi 3B+, so be sure to do an update in whatever Pi 3 (or earlier) you are running before taking the card out and trying it in the 3B+.
Unfortunately, the same is not true of Kali Linux for the Raspberry Pi 2 and 3. Even after installing all of the latest updates, it still won't boot in the Pi 3B+. I just checked the Kali ARM Images Download page, and I don't see anything mentioned there about the new model, so I guess they still have a bit of work to do.
Once you have the new (or updated) software installed, the 3B+ boots, runs, looks and feels just like the rest of the Raspberry Pi family. The difference is speed is noticeable in almost everything you do, starting from booting a bit faster and all the way through the PIXEL desktop and web applications. It doesn't blow your socks off, but it is a clear improvement, based simply on overall user impression. If you want benchmarks and numbers on the various improvements, refer to the Pi Foundation Blog post linked above.
The bottom line on this new Raspberry Pi is that it is definitely a worthwhile improvement on the Raspberry Pi 3 Model B. I am going to leave mine installed in the Element 14 Pi-Desktop box for now, as I think it makes that an even nicer unit.
Think there's a lot you can do with a Raspberry Pi board? With a few low-cost accessories you can get these boards to do a lot more - and thanks to extensive code libraries, you don't need to know much coding.