So this idea is based on a few roomers as stated by Hoopshype's trade rumors page. With Yao being done for the year AND on an expiring contract, it seems natural to consider him a huge trade chip in the coming months. Additionally, the Mavericks are pretty well stacked in their frontcourt and Haywood's minutes are being deferred to a more effective Tyson Chandler as it currently stands.
Houston desperately needs a center and Mark Cuban loves Kevin Martin so how might all this mesh together...
Tayshaun Prince - Houston
Rip Hamilton - Houston
Reasoning: Detroit gets a crapload of expiring contracts in return for roster balance. DeShawn Stevenson's numbers aren't great, but who cares when he's expiring and at least offers extra depth at the SG and SF positions. While Yao will never wear a Pistons uniform, his placement on the IR will open up a roster spot for Artsiom Parakhouski who is destroying souls in Latvia (NOT LITHUANIA YOU IDIOT BOOURNS GOD GET IT RIGHT MORON!).
Yao Ming - Detroit
Kevin Martin - Dallas
Tayshaun Prince (from Detroit)
Rip Hamilton (from Detroit)
Brendan Haywood (from Dallas)
Reasoning: While Rip certainly doesn't provide nearly the scoring punch that Kevin Martin does, Houston has the opportunity to fill their center position on a somewhat reasonable contract, acquire an upgrade/expiring contract over Battier, and still maintain a reasonable replacement for Kevin Martin.
Brendan Haywood - Houston
DeShawn Stevenson - Detroit
Kevin Martin (from Houston)
Reasoning: Mark Cuban is apparently in love with Kevin Martin. Given how well Chandler is playing, and conversely, how poorly Haywood has performed thus far (averaging career low in points and close to career lows in blocks and rebounds all while also shooting only 27% from the free throw line. So long story short, moving Haywood for a player with the scoring power of Kevin Martin would appear to be a near obvious trade considering Mahinmi is playing well enough to fill the 13-16 minutes that Haywood has been playing.
The Issue (as I see it): Dallas is simply playing too well to make any meaningful roster changes, especially one that would warrant a new starting line-up (I'm guessing Martin would beat out Beaubois for the starting spot). Additionally, Dallas is left relatively thin up front while having almost as many guards as the Pistons currently have.
Realistically, Dallas does have the pieces necessary (and for a team like Houston arguably more attractive) to make a trade for both Yao and K-Mart if they sent over Haywood, Terry, and Caron Butler, but that trade doesn't seem likely given how well Dallas is playing and how much they'd have to sacrifice. Realistically, I think Detroit could play an integral part in ensuring Houston gets a replacement for Kevin Martin while getting them real immediate value for Yao's expiring (both contractually and from the league all together most likely). Additionally, Houston did just trade for Terrence Williams giving them more SG/SFs (including Rip and Tay) than you can shake a stick at.
Lastly, I can't see Houston just giving up Kevin Martin for Haywood and spare change based on Haywood's play thus far and Kevin Martin's impact to Houston's team which is why a 3rd team would be necessary to ensure Houston got more value back.