I have developed several web applications with Whidbey Beta 1 including a complete port of a software package of mine from v1.1 to see what changes would be necessary. There were some significant design differences, but the port wasn’t that painful. The big change was that the code-behind wasn’t its own class. It was a partial class that merges with the ASPX at runtime compile. This model is changing for Beta 2. Now, the code-behind will stay a class that the ASPX will inherit FROM, not merge with. Check out Fritz’s post. I think this is a change for the better. There were some issues that arose from the partial-class code file.