So, many people will IIS 7 in hand beginning next week with Vista being available. For those of you have not seen it but are interested,you will need to take some time to get up to speed on the new UI and features. Of course, one of the most practical beneifts of IIS 7 on Vista is that you can make more than one website and it's not limited to 10 connections. It will process 10 requests at a time making it impractical to use as a server - but works great as dev platform.
Be sure to get the version of Vista that has the features you want! THEY ARE DIFFERENT. Here's the definitive list of differences on a feature by feature basis: Notice that Windows Authentication in particular is not available on several versions: http://www.iis.net/default.aspx?tabid=2&subtabid=25&i=1100
The IIS team is working fevershily on IIS 7 on Longhorn Server. It's not quite time to discuss the key features that will be on the server version that are not on Vista, but they are going to be very, very useful for enteprises and it won't impact your ability to develop code on Vista to run on IIS 7 in any core way. If you write an applicaiton on Vista to use IIS 7 features, it will run on IIS 7. In fact, our experience has shown that in many cases, ihttp handlers and ihttp modules for ASP.net run without modification. That is not always true as there are some differences in the environment between the core pipline of IIS 7 and the ASP.net pipeline in IIS6.
Keep in mind also that when you install IIS 7, you do NOT get an IIS 6 (or IIS 5.1) equivalent. IIS 7 is LESS enabled with a default install than in previous releases. Be sure to install the features you need using Turn on/Off Windows features or package manager. See details here: http://www.iis.net/default.aspx?tabid=2&subtabid=25&i=957
Mike Volodarsky has an article about this on IIS.net http://www.iis.net/default.aspx?tabid=2&subtabid=23&i=1223. His blog http://mvolo.com/blogs/serverside/ is also reqruied reading for IIS 7 devs.
Please post problems on IIS.net forums which the team montors. That is the best way, I hope, to get help for your issues and report problems. It absoulety does happen that people report bugs there and they become fixes in the product.
Thanks!
Brett