There's a lot about WebMatrix that I like. In general, I've always thought a fully contained web development system like this is a good idea. They make it simple to quickly get up and running on a site, typically provide high ease of use to help out those just getting started with web development, and also make it simple for more experienced developers to prototype and demo sites and applications.
The download and install of WebMatrix is small and I was able to quickly get up and running with the tool. Along with blank sites, WebMatrix also lets users build a site using templates or by downloading site tools from the Microsoft Web Gallery. Along with the expected ASP.Net sites, WebMatrix can also be used to build PHP-based sites.
Some of the best features of WebMatrix include the embedded servers, the excellent site deployment options and included testing tools, such as a tool that looks for search optimization mistakes.
However, this beta also lacks many features I would expect. If you're doing any actual development and want to work either in direct code or a WYSIWYG environment, you'd be best off using it in conjunction with a more full featured web editing tool such as Adobe Dreamweaver or Microsoft Expression.
Still, this is just a beta and it does have a lot of promise. To check out the beta of Microsoft WebMatrix, go to www.microsoft.com/web/webmatrix/
