Stable.
I participate in 2 main groups of players, both of which have morphed over the years with player leaving or joining, but otherwise being mostly the same.
When I got out of college in 1991, we started a Monday night group that eventually moved to Thursday and blended with a Saturday night group. We've played some campaigns for years (my classic modules started in 2001 and, after a 3 year hiatus, is coming back to continue on) and others until a story plays out. We've played Star Wars (both Saga and d20 revised), 3x D&D, 4e D&D, Call of Cthulhu (both BRP and d20), Everquest, World of Darkness, Deleria, and we'll be dabbling a bit with Torg soon. 20 years after the group started, we've lost a few players, but gained others. At least two of us have been in it pretty much the whole time, most of the rest for at least 13 years.
I also run Pathfinder on Sundays. I've been part of that one for a little over 7 years. We've played PF, 3x D&D, Amber, Champions, Mutants and Masterminds, Feng Shui, and I'm sure a couple of others. We've had a couple of players move away for work, but have otherwise been pretty stable too. We're focused around families getting together to game (with kids getting together to play).
So, yes, my gaming life is pretty stable. Makes it easier to schedule, actually. It's like having a bowling night. You plan around it as much as you can. Plus, the Thursday night group is fairly large (8 players regularly) so if one or two can't make it, we still have a quorum and soldier on.