Great trade for both teams.
The Braves had the luxury of trading one of the best, if not the best, catching prospect in baseball, as well as a highly-regarded SS prospect. Still, Texas doesn't get any elite pitching prospects (I heard Harrison has a bum shoulder and was taken out of the potential deal), and pitching should be their No. 1 concern.
EDIT: Just saw Harrison is still in the deal. It makes it an even better trade for Texas now.
The Braves get a thumper in the middle of the lineup. He's controlled by the Braves through 2008 and if Teixeira has a good 14 months in Atlanta, he might be inclined to re-sign with the Braves.
With this trade, the Braves are now the team to beat in the National League.