"In this post I’ll go through some of the enhancements and improvements done by the CLR team as part of the performance improvements in .Net 4.5. In most cases developers will not have to do anything different to take advantage of the new stuff, it will just works whenever the new framework libraries are used.
- Improved Large Object heap Allocator
- Background mode for Server GC
- Auto NGEN
The information about the new Auto NGen (on Windows 8) was something that I thought pretty interesting. If I read this right, Auto NGen means our .Net 4.5 Metro apps (and GAC'd Desktop assemblies) will auto-magically get NGen'd and thereby likely faster, yet intelligently managing the extra disk space ngen uses.
I do wish it were also available on Win7 though. Being only available on Win8 means it's going to be a number of years yet before it has a significant share of business space [Delete snarky comment about a "Friend" who's workplace is still on Vista]. That said, in looking at it a little more, I can see how it kind of makes sense as a Win8 feature.
In any case, if you're interested in a couple of the base CLR features coming in .Net 4.5 this is a great article.