Douglas Rohm has written up a great article on customizing web builds using MSBuild and the Visual Studio 2005 Web Deployment project. Among other cool things in the article, he walks-through the source code for how to automatically base build-numbers on the current date (he built a custom MSBuild task to-do this).
[Note: we actually use a date-based format for generating build version numbers for the .NET Framework and Visual Studio. This makes it much easier for us to track when a build was produced and how old it is. For example, build 050214 would represent a build generated on Feb 14th, 2005 (the first two digits are the year, the next two the month, the last two the day). Build 050727 would represent a build generated on July 27th, 2005. Note that this last build number was actually the last build we changed the version number on for VS 2005 and .NET FX -- from that point on we did point release naming each day (which is why the official final build is 050727.42).]
One of the things we've been working on the last few days is making sure that the next release of the Web Deployment Project download works with both VS 2005 Web Site Projects (which it does today), as well as the new VS 2005 Web Application Project option we are looking to enable as an alternative web project option (you can read about this in my blog post here). That way you can create companion deployment projects that automate builds, configuration setting changes, and .aspx pre-compilation settings for all types of web projects you create (note: for VS 2005 Web Application Projects you could also optionally just re-use the Web Deployment project tasks within your project MSbuild file directly if you wanted to).
We are hoping to have the first preview download of the VS 2005 Web Application Project option available either this Friday (assuming no last minute hiccups) or early next week. This first preview won't be feature-complete, but it will have enough of a feature-set to allow us to get feedback from the community, as well as to enable enough core scenarios that a lot of advanced developers will be happy with using it for projects immediately. I'll post more details on my blog (as well as a set of tutorials and samples I have been writing with it) once it is available.
Hope this helps,
Scott