I've been using VB.NET 2005 Express Beta 2 and I definitely intend to start using VS 2005 when the final release becomes available. Unless you are developing for a corporate environment that has standardised on the .NET Framework 1.1 or find the upgrade too expensive, I would definitely recommend doing the same. I think VS 2005 provides a better developer experience and the improvements in the .NET Framework 2.0 provide a better user experience.
Mostly everything is the same, but with some new classes and some new members for existing classes. When you open an old project in 2005 it will convert it for you, so there is no big issue. I would imagine that in most cases there won't even be code changes. 2005 can be a liittle confusing because there are more files, but I like the fact that the designer code is in a separate file so all you see is the code you've written. The first point of interest I noticed was the new MenuStrip and ToolStrip, but the old MainMenu and ToolBar are still there. I think it will be the same in most cases, where the old objects will co-exist with the new until some later version where they will be removed altogether.