@Mc
I spent a bit of time hovering over the keyboard before clicking "Comment", even returned a while later to re-read the post, and decided to leave the post as is. It just needed to be said.
If you check Microsoft Connect, you'll see that there are quite a few outstanding issues related to performance and access to the CPU and GPU. These issues date from as long ago as 2004 (lack of support for numerical operations in generics). There is still really no way to fully or easily access the power of either the CPU or GPU through .NET without dropping into native code, and even there you're dealing with thunking issues. This matters because .NET is the primary development platform for mobile devices, and these devices are underpowered relative to the desktop.
I fully appreciate that the old C/C++ infrastructure for the VB/C# compiler needs to be replaced, and that there is a nice upside to this in that it simplifies support for refactoring and other IDE features. However it's simply far more important to address the performance issues with the platform as a whole, and to recognize that it's primary use is no longer necessarily on desktops with desktop level cpu power, and not necessarily being used to write desktop web or LOB apps.
posted by bcooley