Joe Duffy, a PM on the CLR team, has a great article up about concurrency and reusable libraries. He’s been posting concurrency- and scalability-related articles for a while now. The article (and his blog in general) are worth checking out if you’re interested in that sort of thing.
In particular, he opens up with predictions of >100 core chips within 4 years, which will necessitate a major re-think in the way software is designed. I’ve been getting into arguments along these lines with everyone I meet this week, and I think I have almost convinced some of them. 
Anyway, more on that later.