The majority of users are not in North America and have economies that are as-yet unaffected by what's going on there.

Yes, though, there *is* an inevitable connection between SL and the physical world - everyone in SL is from the latter, after all. It's difficult to say exactly what external factors influence SL, at this stage, and in what proportion.

Virtual worlds might be older than the Web, but they've had quite a bit less research done on them.