The Mavericks sit in third place in the West, with first and second out of reach due to their slow finish. They lead the Oklahoma City Thunder by two games in the loss column and have five games remaining on their schedule. Since Dallas has the tiebreaker, they would have to lose three games in the standings, and it's not likely to happen since OKC has a home-and-home with Denver and a road game with the Lakers still on their schedule, and the Mavericks having thre lottery teams remaining on their schedule. It would also park a dark cloud over the AAC, since the Mavs are already on a depressing three-game losing streak entering their last five. But just from a matchup standpoint, it might not be a bad thing.
Dallas would meet up with Denver in the first round, rather than, most likely, Portland. Denver is hot. They've won six straight and are 15-4 since the Carmelo Anthony trade. Portland is hot, too, though, and they just demonstrated why they will be a difficult matchup in the first round. Denver has talent, but they lack an elite player, and we know what elite players usually do in the playoffs.
The other factor is delaying a potential series with the Lakers to (almost certainly) face the Spurs if they make the second round. I think that's a plus for several reasons. First, the only way that I can conceive of the Mavericks giving the Lakers a series is with a healthy Caron Butler. The chances of him being back and effective by the conference finals are slim, but they're greater than the his outlook for the semifinal round, which is a near impossibility. Second, the Lakers aren't likely to lose in the second round, but OKC has already given them one tough series, and they have more size this time around. Third, while the goal is obviously to win a title, we would be crazy to not prefer a three-round playoff run to a two-round playoff run, even if you can't beat or avoid the Lakers.
↵It wouldn't be a pretty sight for Dallas to finish poorly enough to fall to the four slot, but it would make for an easier road.
↵And while we're on the subject of the Thunder, LJ Rotter of Mavs Moneyball had an interesting discussion with Welcome To Loud City, the SB Nation Thunder blog, about the two teams. Here is the Thunder side, Mavs side.