Everything in Dallas revolves around Dirk Nowitzki's shaky health.
Dirk, of course, is still amazing (when healthy). He possibly remains the most potent big man scorer (when healthy) and the most deft shooter among 7-footers (when healthy). His mix of scoring and rebounding (when healthy) is a just a huge boon to a team on a nightly basis. He's been consistent throughout his career, and figures to continue that (when healthy) as he ages.
With that said, the big X-factor for the Mavs might be the guy a lot of folks wanted to see in Boston. OJ Mayo.
O.J. Mayo is capable of scoring in droves, but is just as streaky as his predecesor, Jason Terry. The difference is, he's a significantly better defender. And don't even get me started on Elton Brand and Chris Kaman. Ok fine, get me started. Watching big men OTHER than Dirk Nowitzki who can score is like watching a unicorn dance across a double rainbow. Kaman can score all over the court and isn't afraid to body up and shoot a hook over someone's head. Brand has an accurate midrange shot but is also big enough to have his way in the paint.
But at the same time, it's not quite clear how the Mavericks see Mayo. Are they hoping he can be their starting shooting guard for many years to come? If so, they will need to coax Mayo's all-around gifts out of him more effectively than the Grizzlies could. Are they hoping he can function more like Jason Terry, who was an excellent player that was nevertheless a bit more incomplete? If so, they need to give Mayo the green light and not worry about his shooting inefficiency. The answer is probably somewhere in-between, which is the problem with Mayo. He can do a lot more than he's capable of doing, but he doesn't, and teams have to decide whether to work on getting more out of him or settle for him in a lesser, more specific role.