Today is Windows Phone Mango day with updates starting to roll out and some other promised services starting to go live. Microsoft said there would be a web-based Marketplace, similar to the Android Market, and if you go to www.windowsphone.com/en-US/marketplace right now you should see that it is live. You will also find there is a new unified My Windows Phone page where you can manage your Xbox LIVE profile, LIVE Mail, SkyDrive and Find My Phone settings all on a great looking site.
The new web-based Marketplace should help out quite a bit with app discovery and once you find an app you can choose to install it right from the website. There are also options to Like an app on Facebook or Tweet about it on Twitter so you can share it with your friends. I really like that I can now rate and review apps I have loaded on the website and plan to write a lot more of these now that I can do it from a computer and not just my phone.
You can choose to download the app immediately to your phone using messaging or email instructions for installing the app later. If you have multiple phones in your profile you can choose which phones to install the app on too. I tested it out and this new service install the app on your phone without you having to do anything else at all on your phone, assuming it isn't so large as to require a WiFi connection. This is slick and makes Windows Phone even better than it was already.