Ruby and other gems describes a fascinating framework built by Gemstone, a New York outfit you probably never heard of. I personally think that something like this might be huge in terms of making Rails scale effortlessly to really big problems.
Interestingly enough, Gemstone is located in Portland, OR (not NY) - not terribly far from Tim, as it happens. Also, it already takes an OO language into some really huge places - like container shipping and financial trading. That OO language would be Smalltalk though :)