Well, there's a good reason for the bittervet legions spending more time complaining than actually doing stuff. "Stuff" has already been done and it was good. Mostly. Other "stuff" was also done and it was terribad. Sometimes. Now, it's not that easy. There's very little left to do that can both be innovative and remain... well, not silly. This mostly leaves doing "stuff" that's already been done, but the second time around is never quite as good as the first. The third, fourth and fifth time it starts getting stale as fuck.
There's a fuckton of experience aggregated in the various veterans around here (I actually count myself as one of them, even though I'm winning Eve and came along later than the real old grumps) and it's starting to become very easy to recognize rehashing of old stuff or the inherent gnnerghh-that's-just-urrgh of most new ventures. There is an undeniable stagnation of both the game and the community and it's rather unavoidable when Eve moves at the current pace.
New game mechanics aren't really going to fix it. Adding a pirate militia function will be a fleeting salve upon the rash until it turns out to be no more invigorating than FW turned out to be. Same goes for just shuffling around game mechanics for warfare, fw, nullsec, w-space and what have you. They're not going to address the core of the problem, which is that character motivation and character progress relies on the universe shifting around them as much as they shift around the events of the universe.
The only real way to reinvigorate the veterans is to actually shake things up rather severely. Have the Minmatar Elders fuck off with half the Republic and ram a massive wedge between the Republic Remnant and the Federation. Have the State and Empire fall out, hell have a WAR. Huge political shift in the Empire as it shears down the middle between a new far more secular faction against slavery and the religious side, whatever. Similar things among pirates. Hell, kill off some factions/subfactions and create brand new ones.
Some major upheaval that allows older characters that have invested time and effort, been shaped and guided by New Eden, to face a new New Eden that demands action and either renewed or shifted allegiances in the new landscape that forms around these cataclysmic changes. We already have all the game mechanics for a proper sandbox. We just need to raze a few of the towers and castles we built so there's room for new battles and motivations. Take away the blankets we've covered ourselves with and gotten too comfy in to willingly shed, so we as characters are forced to go out and get new ones, probably by taking it from someone else.
This will also actually allow you to change your character and try something new without it being contrived and an obviously OOC thing to try new pastures, which is something that's always rubbed me the wrong way.
The actual difficulty for CCP is in reality rather low. Most of the work would be in writing the new PF, making it believable and new worldcrafting etc. Turn the militias into a four way battle instead of a two-way battle would take some work, but it's hardly insurmountable. Deleting a few factions and popping a few new ones in there with blank standings slates shouldn't exactly be too daunting either.
There's only so much that can be done by a roleplaying community when the framework that surrounds it remains rigid and stagnant, especially when the characters have been slotted nicely into a comfy niche and shifting it around frankly becomes both unrealistic and the other niches remaining the same as they've been for years anyway. Take away half the niches, create a few new ones and you'll see a roleplaying community that'll break out the heavy machinery to tear shit up and fill the craters with new content.