As you probably heard, the Thrashers retained the No. 3 pick in the 2008 draft.
My current favorite pick in that slot (and he is expected to go around this time) is defenseman Drew Doughty out of the OHL Guelph Storm. He's really dynamic, which you need these days in the NHL. Craig Hartsburg recently called him the best defenseman in junior hockey. As the outgoing coach of the Canadian junior team, he would certainly be in a position to know.
Here's a link to a Q&A with Doughty from Hockey's Future. It's from January when he competed in the Top Prospects game.