If you were worried about the performance of a new application you were creating, would you pick WPF? What if it was critical that the application be fast? Would you pick WPF? I think Microsoft is overselling the performance of WPF still. I was hoping that WPF in .NET 3.5 would contain some nice perf enhancements, but nothing much seems to be listed (and I'd expect that they would).

I don't want to buy a new machine to make a marginally "better" application faster. That's true of nearly everyone, especially businesses/enterprises.

Pablo suggests WPF for an application that requires: "Fastest possible 2d grid control."

I personally think that's the wrong way to go. WPF isn't ready for super fast applications. The reality of most developer's days is that they don't have time to "evaluate" technology options much; maybe time to decide should they use a flat button or a 3D button, but they just need to get their work done. Microsoft absolutely needs to provide better prescriptive guidance in these cases that aren't self serving to a particular product/team whenever possible. (In this case, the developer was already committed to C# it seemed, so they had already picked a Microsoft platform).

What do you think? Comment here, or on Pablo's site.