Not much to say other than that it is REALLY cool to see MS developing stuff in front of your very eyes. http://www.start.com/3
Let's get technical...
Which brings me to a software development issue I've run into recently... Versioning web applications. Obviously, it would be nice to simply upgrade everyone to the same platform, which is a really a key feature of web applications. However, what about drastic changes to interfaces? For web applications that have active membership througout the year, this issue can apply, but usually doesn't.
For web applications that have paying membership for a set period of time (begin and end dates), you have the flexibility of selling them use of the product and they go away. During that time, it may or may not make sense to upgrade them to the new interface. If it makes sense to keep existing customers on the version they paid for, then that brings up the issue of how to version a web application, interfaces, and even parts of an interface.
Obviously, you can version a web application by simply copying the new version to a different url and having new customers use the new url. Interfaces present the unique problem of identifying which customers see what. Obviously this can be controlled through a database of customers and a pointer to which interface they end up with for the same page. The concept of "skinning" an application also addresses this issue. I have yet to see a truly elegant solution to web application skinning (because I believe XSLT ought to be a big part of it, but that it should be independant of the programming technology and allow dynamic content replacement and possibly even support for things like ASP.NET controls). The Community Server Forums application provided on ASP.net made a good attempt and DotNetNuke definately made an incredible tackle. PhpNuke was a mess. Skinnable controls can be purchased on the web which are also "good". However, I felt they all fell short.
Having tried my hand at tackling the problem in a limited amount of free time, I also fell short of the goal. Learned a few good things, but all-in-all ended up with a bunch of code I'll likely never use. Developers are welcome to point me toward examples they feel best exemplify web application skinning and I'll try those out when possible...