There have been some serious issues for the rollout of GTA Online - but I did get to play over the weekend, and it was amazing.
I have experienced some of the problems everyone's talking about - the character I set up over the weekend has now disappeared into the cloud. Rockstar says they are working to restore all characters like this, but I'm not holding my breath.
I only spent 3 or 4 hours on the introductory stuff, and didn't really accomplish anything, since i was just learning.
Note for those of you who will play GTA Online at some point - the initial setup and missions the game forces you through is about an hour to an hour and a half of time.
When more bugs get ironed out, I'll let you all know when you should sign up!