Sielle: Keep in mind that the mektek guys were able to get MS to give up the Mechwarrior 4 license for free. It can be done, but you actually have to work at it not just say "Hey I want this!"
Lockmat: They don't own this license, but they have an understanding with the people who do. You're new here, aren't you?
Sorry, I couldn't resist :)
I'd do a bit more research before you start to throw stones, if I were you. MS purchased "FASA Interactive" back in 1999 which included the license to the following games as well as the rights to release video games based on FASA's IP;
(note: some games were released after 1999, but as the studio was owned by MS at the time MS owned the rights to those games as well)
MechCommander
MechCommander 2
MechWarrior 4 Vengeance
MechWarrior 4 Mercenaries
Mechassault
Mechassault 2 - Lone Wolf
Crimson Skies - High Road to Revenge
Shadowrun (PC/Xbox 360)
In 2007
Microsoft licensed (note: licensed, not sold) the rights to produce video games based on FASA IP back to Smith & Tinker.
So to sum up, yes MS did and still does own the rights to Mechwarrior, and it was MS legal that was the hold up on the mektek release of MechWarrior 4.