I've been GM and officer in quite some guilds. It all comes down to what the guild is like. If you're the GM of a casual boxing guild, nothing is required exept for being online reguarly. If you're officer in a guild that wants to raid and make progress, then it requires a lot more effort.

If it's a nice guild, it should be fun to be an officer. I've had like 5 serious officer meetings in the past 3 years though, so here again. It comes down to how your guild deals with things.

So if you're allready doubting wether to be an officer, I would skip it. Since it might require you to be online when you don't want to -> drains fun out of wow. -> your loss.