Guess I'll throw out some ideas. Some might be bad, but hey, they're ideas:

PVE:

Current raids: Everyone brings some toons, we go in to LFR, we kill stuff and get killed. Later on progress on to harder modes if viable.

Dungeon races: Setting this is up is a bit of a nightmare depending on how we wish to do it. Getting the same keystones, coordinating start times etc might be next to impossible...

Legacy raids: Not mog farm, but fresh teams without heirlooms, clearing all the old raids at their relevant levels. Frozen XP if necessary.

Raid achiev farms: I've done most of the ones I want, but up for getting them for people who don't have them, or doing the ones that are still hard to box/solo.

PVP:

5v5 skirmish tournament: Fairly self-explanatory. Hit stuff, see who lives. Think 5-box is the most common number anyways. Or I suppose in theory we could try 2x5-box vs 2x5-box in an RBG setting. Could be interesting with the objectives. Would require large numbers of participants though. Hell, if we get enough numbers, doing 20v20 or even 40v40 would be great fun and make for interesting videos.

WPVP Events: New raid opening? We go to the entrance and have some fun. Good quest hub to invade in an upcoming patch? Same thing. Naturally from atleast COA we need to phase over to some alliance heavy PVP realm. That should not cause issues though as I do that at times myself.