I just finished getting AJAX 3.5 working on SharePoint 2007 for an internal project I'm working on, and now I learn that we are going to be migrating our server from a Windows Server 2003 VM to a brand spankin' new Windows Server 2008 box. So I reimaged my machine with WS2K8, installed SharePoint, and got everything working.
This post will be just a list of things that I ran into moving a user control and a workflow with a custom edit form from WS2K3 to 8. The biggest thing to point out about Windows Server 2008 is that we are starting out in .NET 3.5. Windows Server 2003 shipped with 2.0, on which SharePoint was built.
(The only reason SharePoint 2007 requires the 3.0 Framework is for WF; it is a 2.0 web application.) So when you get all your SmartParts, custom code, and workflows working on 2003, everything is by default talking to the 2.0 or 3.0 versions of the framework, which are already installed.
When you start targeting 3.5, things get hairy. However, if you read my blog entry above, it's not too hard to get 2.0 and 3.5 SharePoint content running side by side. The problem with WS2K8 is that we are already in ASP.NET 3.5; anything talking to the ASP.NET AJAX Extensions 1.0 will fail!
So here are some of the bridges you'll have to cross to keep your controls that were happy on WS2K3 from becoming grumpy on 8:
So the moral of the story is that if you are moving AJAX SharePoint 2007 content from WS2K3 to WS2K8, get over yourself and install ASP.NET AJAX 1.0 on your server. Despite the assembly binding redirects in my other blog, you still need the old System.Web.Extensions and System.Web.Extensions.Design DLLs in your GAC for everything to work easily. Have fun!