Speaking from a strictly roleplayer/social standpoint, I would love to have the guild limit increased. Right now (to my understanding) we can only join four or five guilds. As someone who likes keeping their RP dudes separate for the sake of narrative, it’d be nice to have a handful more to join.
I could see other reasons for this as well, assuming people would want to join smaller, more personal friend guilds, PVP and WvW ones, dungeon running ones, and maybe even just straight up social ones.