Breaking news! Piranha games has just announced that their next MechWarrior game is going to be online! Creatively dubbed MechWarrior Online, a lot of details outside of a tentative release date (late 2012) remain to be seen, but it seems as though the team really wants to bring MechWarrior into the online space. Currently, MWO is confirmed to be a free-to-play game with microtransaction purchases. Aside from Perpetuum Online, this may very well be one of the first major robot MMORPGs to hit the market. From Software, if you don't cough up Armored Core Online soon, I'll be just fine with MechWarrior Online!
You can get more details at the MechWarrior Online website and FAQ (does anyone else find it odd that one of the most detailed questions is whether missiles will be guided or not).