Among the new features in release 3 is code profiling (pro version only). Profiling lets you see where your code is spending its time. It’s very handy and is a most welcome addition.
The compiler now supports Attributes which allows you to do some fun stuff with compile-time metadata. You can see Aaron’s blog for more info on attributes.
They’ve enhanced the check project/item to provide feedback about problem areas. In particular you’ll now get warnings about code that is deprecated. This was one of my wish list items: compiler warnings.
You can have constants and enums inside of classes now as well. There’s also the usual mix of bug fixes and stability improvements – especially in the Windows builds.
The only issue I know of is with Einhugur plugins. The IDE will now complain that they’re using the old style constructors (the class name) but thankfully RB can do a temporary fix until the plugins are updated. There’s also an issue with the Einhugur plugins not getting keydown events. Fogbugz entry here. This appears to be a Mac only problem but the Fogbugz entry hasn’t been updated yet.
So all-in-all I think this was a pretty good release. Even the documentation is updated with the new attributes information. Only time will tell, but for now I give RS kudo’s for doing a good job.