A quick update about trying to upgrade to VS2010:
- VS2010 does not have a version of BIDS (Business Intelligence Development Studio). This means you can not modify certain classes of Database Projects in VS2010, like any SSIS tasks. I was lucky, all my SSIS tasks are in seperate solutions from the rest of the projects for my code. If your's aren't, you'll need to extract them. VS2010 will happily update an SLN file and simply disable any DTPROJ files in the solution.
- VS2010 can not cross-compile .NET 3.5 Test Projects. If you're doing any Unit Testing, your Test projects will be automatically updated to .NET 4.0, even if you're trying to stay on .NET 3.5 or lower for a little while. You'll need to either disable your Test projects, or be prepared to upgrade everything to .NET 4, even if you're don't want to (or are unable to)
- Not a VS2010 issue, but Workflow Foundation 4 doesn't support State Machine Workflows (yet), so if you're using State Machine Workflows currently, you can't update to .NET 4 at all.
Actually #3 is a huge issue, since there is no timeline on the state machine workflow support for .NET 4 (other than it's been stated that it is being worked on). Basically, we're down to the choice of forking our solution files, so that we have some that are VS2010 solutions running .NET 4, and some that are VS2008 solutions running .NET 3.5, or simply not upgrading to VS2010/.NET4 at all, since we have interdependencies that complicate the issue (we strive to adhere to the DRY principle). I was really looking forward to VS2010, but the reality of the situation has tempered my enthusiasm drastically, between pointless incompatibilities (unit testing) and feature regression (state machine workflows), it might be a while before we're able to upgrade.
I'm disappointed. Really disappointed.