Right now I think Mark Cuban has done an admirable job making moves after Tyson Chandler left to keep Dallas competitive however having Brendan Haywood and Ian Mahinmi playing center or having to play small is going to hurt the Mavs. I love the Odom trade, Cuban got him for pretty much nothing. He is not big enough though to play center. The Mavs have a plethora of wings though that could be appealing in a trade for a big.
My favorite center option is Anderson Varejao of the Cavs. He would be a fantastic fit for Dallas. He is very underrated and one of the very best defenders in the NBA. Varejao is such a good defender that he elevates the defense of those around him. He provides comparable value to Tyson Chandler at half the price. Varejao is injury prone and would cost the most, but I think he's worth it. He together with the other recent additions would make the Mavericks even better than last season.
Possible trade: http://espn.go.com/nba/tradeMachine?tradeId=cvk46lz
The only real player of value the Mavs give up here is Roddy B who does still have a lot of potential. He can be replaced though by resigning JJ Barea. All the other players really don't hold much value for Dallas and would only serve minor roles. The Cavs though are getting younger and adding depth at the wings with some potential while clearing the log jam at point guard a little.
with a bench of Odom, Terry, Haywood, Rudy Fernandez, and JJ Barea
The rest of the roster can be filled with minimum players. I think this trade along with the previous moves made make Dallas the best team in the West and the favorites for another title run.