Well in a recent NGNG podcast they said they haven't even considered a reinforcement pack because they started working on other things. Since they have different people doing different things, maybe the mech guys are working on Community Warfare stuff. Afterall, last I heard they were going to have at least Turrets and Dropships in CW. Possibly they'll have some vehicles as consumables (Good luck with programming the AI pathing, and I hope you have a command wheel for them) as well because it sounds like they are doing some sort of EvE online sort of things where you try to defend planets.
That's just a guess though. Though, if people really really want mechs that bad they might just focus on releasing those mechs instead.
I will say, they seem to have picked up their pace lately. Of course, this could be a bunch of stuff they were doing behind the scenes before, and now they've finally gotten things being rather finished. I just hope they are still thinking about how features are implemented. Gotta have the right balance, because if you go to slow nothing happens, you go too fast and you'll have a bunch of crappy features. I just hope they've found the right balance.