I logged into my paladin over the weekend to clear out the quests in Dustwallow Marsh. I also left the guild that toon joined a couple weeks ago. I wrote a little of this last week. There wasn't much activity at all in the guild, and the officers weren't on for more than a week. I decided that perhaps exploring other options would be the best way for me to go.
Will I join another guild at some point? Probably. Do I want to join one now? Not really. If I get an invite, of course I'll try it out despite my shoddy history with guilds (most due to no fault of my own). From my experience playing the pally, having a guild really isn't necessary, especially with the new LFG tool. Sure, can guildmates assist in other ways due to professions and game knowledge? Certainly. However, having another alliance toon at 80 means that for most part, I know what to expect from quest chains, etc.
I could make the argument for the social aspects of guilds. Sure, it's good to be chatting about random stuff with other players while questing, but it's not a requirement for me. Due to being guildless/having a non-active guild for so long, I've grown used to the silence, and it's peaceful. No drama. No fifteen year-old spamming guild chat with stupid stuff all in caps.
I'm a little picky about a guild I can stay in long-term. A good guild is only as good as it's members. A good guild should have helpful players who make the game fun, who impart their knowledge, and add to the overall experience of playing WoW.