CCP has released their Quarterly Economic Newsletter for the 4th quarter of last year in EVE Online, and the word is "growth." They saw big increases in trade volume and value all over the place on the market. Which isn't surprising, considering how much their population surged late last year, thanks in large part to the well-received Trinity expansion. And the growth isn't done -- CCP expects to see 250,000 subscribers by the end of Q2 2008.
There are lots of great numbers in here -- apparently only 9% of players are out in low sec space (much lower than I'd thought). Jita is still a madhouse (no duh -- you'll already know that if you've ever tried to go in there on a weekend). Finally, they've introduced a new tracking variable, called Gross User Product, that is the value of all services and goods produced in a period of time, minus the amount of goods and services consumed. In other words, a GDP, but for a virtual world. They don't have a figure yet (because it has to be tracked over a period of time), but the next QEN should have some even more interesting information on how we might track virtual economies in MMO games.