I am still playing and planning on joining flex raids as they come around. But I'd be happy to join any that friends join (Horde side). I just refuse to be the leader who puts them together. That part of my life is over and done with.
Edit: For those that still don't have it, blizzard id is Jomero#1770.
And NephyrS, if your server happens to be a part of the same realm as mine when they merge, you are more than welcome to join my guild. It's extremely small, and was created mostly for myself and my two friends (and occasionally a couple others as well as my wife) who are still actively playing. We got tired of being in a guild where just the three of us leveled it to 25 and yet we still had no control over it (as well as come up with a better guildname). So in january I created my own guild and 3 or 4 of us got it to 25. We came up with a name to show our disdain for Garrosh: Thrallguard (his personal elite guard)
It is the very definition of casual though. We don't plan stuff. We don't do events. We don't even actively recruit. It's a guild created by friends, for friends. Any drama of any amount gets a player booted. About the only thing we do that's coordinated is "Hey, you want to join me in the LFR queue?" "Sure." Or, "Hey, you want to do a heroic scenario?" "Maybe. Tomorrow?" "Sure."