I`m currently working on a ASP.NET MVC sample website and look around for nice helper or implementations on Codeplex. Here is my (small) list:
"Never trust user input" - validation is very important - this is intresting way with ActionFilters and jQuery.
4 new Viewengines, Code Snippets, Extensions and so on...
Do you know any other nice "AddIns"/Implementations for the MVC Stuff?