I have a level 60 Night Elf Hunter, geared with a mix of Tier 1 & 2. I ran in (and lead for a stretch) a PvP group, but retired at Commander. Took alot of fun out of the game for me, it became like a job. Our 7th Grand Marshal graduates on Tuesday, and our 8th the week after. I am in what I definitely would call a "casual guild", but we are currently running Blackwing Lair. We have some real talent in the guild, but I don't think any of us want to get trapped in what you see going on with most of the "hard core" guilds. Very friendly and laid back, we would like to think we have a family friendly atmosphere, and we frown upon general vuglarity in the guild.
I had actually left the game last December for about 5 months. I hit that "level 60, where do I go from here?" place, and flat out dropped the game. After 5 months and alot of badgering, I came back with my level 60 totally naked, with not a single item in his inventory, and 26 silver to his name. The lesson learned? If you are going to leave WoW, don't sell off everything you own, give the money away, and then delete your character. Just close the account, it will all be waiting for you when you return.