Professional isn't too bad (<$500/seat upgrade), and I guess Enterprise Developer (VS2005 ED) might not be too bad if you're already paying for MSDN Premium, otherwise it's way more expensive than before - at about $2300/seat upgrade - since you have to get it with MSDN Premium.

VS2005 Enterprise Kitchen Sink is about $10,000/seat, not including the various server thingies (TeamServer?)

We have VS2001 Enterprise Developer, looked at the price to upgrade to VS2005 ED, laughed, and upgraded to VS2005 Professional. I saw no value in VS2005 ED, since all the interesting extras have open source equivalents that are probably better (e.g. Subversion for version control, NUnit for unit testing).

The big advantage of .NET 2.0 is, of course, being able to run IronPython.

--Tony