While Martin has been a fan favorite, he does not have an NBA body and I feel his injury situation the last several years is probably going to continue wherever he plays.
Landry is a plus as the Kings are trying to toughen up with guys who hate or accept losing. Martin is kind of on the soft side, though as a role player on a team otherwise mentally tough, he could lead a team like the Rockets in scoring every night with a better distributing point guard like Brooks.
McGrady is likely going on to the Knicks before the hour is out. But the Kings are playing hardball on what they want back. Petrie would like,(in fact, has ALWAYS wanted) David Lee in return, or he may just end up keeping McGrady and let him go with a buyout this summer. Otherwise, it looks like the Knicks are only offering Hughes, Jeffries and draft picks, but we will see if Petrie bothers with that.