Man, if there was a MMO Mechwarrior game, Id retire from the Navy. It would be such an awesome game, especially if they could incorporate more then just Mechs.
FLYNAVY!
I would die a very happy man.
Just think of a Mechwarrior MMOFPS.. with a Planetary setup.
OMG I just got a boner.
If someone made a battletech game like planetside and without the pay 2 play i would never play another game again. 
Been thinking this ever since I first play'd Planetside, 24/7 PvP Mech v Mech how could you go wrong , oh right BFR's trust SOE to monumentally screw up Mechs
, maybe they'll sell thew rights to Planetside 2 to someone that has a clue
still thinking why the hell hasn't someone made another proper persistent FPS MMO without NPC's ?
Unless they do sell it to another group... or get ALL new devs.. PS2 will suck ass.
Or, get the original devs back.
It's the "new" devs that screwed it up, especially when Dave Georgeson left.
There were some great devs originally for PS....you just have to look at the concept and the scop of the game to realise that great minds were at work.
Things went haywire from Aftershock....the BFRs were just horribly overpowerd, caused a big drop in FPS for many and frankly just didn't fit in with the rest of the tech in the game....even if now they are a shadow of what they originally were. However it's still the ONLY game like it out there...nothing else has the same scope or size or pure freedom to choose your target, either a pure territory grabber or a slightly more subtle benefit denial. If you haven't played it for a while..take the time to go back...it's still great fun when you get an outfit all on Teamspeak

If a game developer could make a persistent Battletech Universe...say of 20 worlds...each with 5 or 6 impotant targets (factories, communication arrays, cities etc). It would be fantastic to have 2 factions fighting for control of these. You could have some AI controlled turrets or militia forces at each target but a successful defence would almost certainly require player input.
You would be able to use strategy to decide on targets....diversionary attacks, raids or full invasions...and then tactics to fight the individual battles based on the terrain etc of the area around the mission objective. It would be perfection if you could start with the orbital insertion, dogfights going on while the huge dropships raced for the landing sites. Even if you just started from the point where the mechs disembark and head out it would still be great.
Free to play? Meh who cares....I'd pay twice what I do for Planetside to play that baby

Anyway....a persistent Battletech MMO of just about any type would surely be a HUGE hit...something a bit refreshing instead of the same tired old nonsense the market has descended into now. How many pointy-eared-pixie-loving-same-game-as-the-last-but-with-a-different-skin/UI do we need?