Microsoft published a very comprehensive product comparsion page.
It contains over 450 features in 25 sections, comparing 11 products.
It is really worth looking at it:
Visual Studio 2008 Product Comparison
ADD: 2009-05-29
(this link seems to be out-dated, for a complete data-sheet see:
Visual Studio 2008 Product Comparison Guide
Starting with Vista, MS introduced the new Windows Error Reporting API (WER) and removed Dr. Watson from the system. The WER-System now directly sends by default the data to WinQual. They also changed the behaviour, that a minidump is only generated if the WinQual-Server requests this. So by default there is no way to get to a local minidump if you are not registered at WinQual (which costs 400$/year).
Several ISVs complained about this issue. And now MS added a new feature in VIsta SP1 and W2k8 to allow the creationg of local minidump regardless of the WER setting. FOr more info see: