Mono's SIMD Support: Making Mono safe for Gaming - Miguel de Icaza
This is an awesome development. If the numbers continue to holdup, this could be a mega improvement from game development and general code performance improvements.
The only thing to keep in mind is when new features of processors are added, you have to extend the runtime to accept them. But in all I think this innovation should be part of the core ECMA CLI specification so that the performance for gaming can be vastly improved.
Mono's SIMD Support: Making Mono safe for Gaming - Miguel de Icaza