Jeffrey Palermo recently commented about a discussion he and the CodeBetter guys had with Scott Guthrie regarding adding new support for MVC within ASP.NET. While I didn't get a chance to talk to Scott, I hope they look at other features that current MVC frameworks provide that make the development cycle more fluid.
For example, the process of extracting values submitted from the form can be tedious. Within MonoRail, the MVC web framework provided from Castle, if your controller inherits from the SmartDispatchController, you can take advantage of data binding back to the action of your controller. This can be accomplished either in the form of individual parameters within the action method mapped automatically from the posted form or as a CLR object passed as a parameter into the action method. The latter happens when using the DataBindAttribute on the method parameter of the action. This is an example of something we have to do in one form or another and MonoRail removes the redundancy for us.
Many times large companies are hesitant to use OSS due to the licensing terms or the potential lack of support for the product. Castle Stronghold, a company formed by the creator of the Castle Project offers support for their products. Hopefully with this initiative the use of OSS will become more accessible to the development community at large.