I've always wondered what a MMOFPS would actually be like - I think I'd like to at least try one before I finally make up my mind.
But then again, what do you actually do when you're not fighting. In RPGs that's pretty easy, exploring, crafting etc - and you have the option of PvE or PvP - this would obviously be PvP only.
I'm also thinking about how a battle could change based on the time of day/week - when weekends start there would obviously be a massive influx of players.
I think I'm gonna go do some reading and vid watching this evening