When Visual Studio "Orcas" ships, we have a question we need to answer: which version(s) of the .NET Framework/WinFX should it target? Having a single tool that can target various runtimes has been something I've been a strong advocate of for years, but my experience with the Express products has softened my passion. Why? Because not only is multitargeting (the term we use for enabling developers to choose which version of the runtime the tool targets) very hard to implement (thereby sapping feature teams from work on other features) but it is also something that can be extremely confusing.
Just imagine that you're new to .NET (as nearly 2/3 of Express users are) and you're confronted with a dialog box early on in creating your first project that asks you to select the version of the .NET Framework or WinFX you want to target. For most, the choice would either be the default or "Game Over."
I'm actually advocating that whatever "big" VS chooses to do, that Express only offer the latest version of the runtime to be targeted. That we either forgo entirely with the concept or hide any tool UI for multitargeting. This would help reduce concept count considerably. Of course, if you wanted to dig around in some config files, you could make Express do whatever you wanted, but the UI concept count would be kept low.