If anyone thinks this trade eliminates Dallas as a contender, you're not very intelligent. That would still be their core of Terry, Nowitzki, and Howard, along with Kidd. Yes, the players they are giving up cause some problems for the Spurs so that would be a good thing. But their big three will still perform like they always do against us, and any other team.
I also think it would be interesting for the Spurs to try and get Diop away from the Nets...exchange some expiring contracts maybe, who knows.