Only if you considered the Mavs legitimately better than the Spurs to begin with; I didn't. I think this trade gives them the potential to be and I agree that the Spurs need to do something, preferably acquire Thomas, but the Mavs still aren't legit contenders with this trade and the problem lies in the core. I consider Butler a legit number two star, but when it get's down to the money season and in crunch time in a playoff game, I'm not confident in Nowitzki, Butler and Terry, as the three main scorers. I'd take Bryant, Gasol and Odom, Anthony, Billups and Nene and Duncan, Parker and Ginobili, before I'd take that trio.
The Mavs are capable of getting past the Spurs with this trade (mainly because this gives them a second center to throw at Duncan and he happens to be better than the in bent), capable of getting past the Jazz, maybe even the Nuggets (though I doubt it), but there's no chance they beat the Lakers in a series and really, that's what it's all about. It's not about going from being the 4th or 5th best team in the conference to the 2nd or (far more likely) 3rd best team in the conference.