It's fantastic. Downright fantastic. Even in portions that deal heavily with memory directly (e.g. our AMD PCnet driver), we get the ease of use that Boo and .NET give us. After working on this iteration of Renraku, I don't see myself ever using a non-managed language for OS work again.
Do you use Boo's macro facilities ? I also saw that Boo has got pointer manipulation facilities. Do you have to use that in the low level (-> drivers) parts of your code ?
EDIT : I'm following your project since the beginning. Many kudos on your work :)
We use Boo's macros now and we'll be using them even more soon. We don't use Boo's pointers, however. They didn't exist when Renraku began, and our pointer intrinsics are considerably more powerful. We use direct memory access in a few drivers and system initialization, but that's about it.
