UPDATED: Links fixed...our apologies for the bad URLs on the images.
I just ran across some really nice How to videos from Scott Hanselman on the ASP.NET MVC Preview. They are very much demonstration-oriented and very explanatory.
#1 | MVC Preview - Part 1 - Displaying Data
16 minutes, 41 seconds
#2 | MVC Preview - Part 2 - Editing Data and Making Forms
18 minutes, 38 seconds
#3 | MVC Preview - Part 3 - Advanced Techniques
12 minutes, 56 seconds
#4 | MVC Preview - Part 4 - Testing
23 minutes, 20 seconds