Have you really dug into the content yet, though? I know a couple members of my guild decided they would rather spend the day farming Adamantite and Mana Thistle in the 'old' Burning Crusade content because it was mostly abandoned. While it isn't fresh and exciting, it is certainly making them quite a bit of cash.
Me, personally? I jumped in feet first. As soon as the servers came up I was flying to Quel'Danas and putting together a Magisters' Terrace group. My original intent was to get the new daily quests out of the way first, before everyone got home from school or work or whatever it is they do, but the server wasn't agreeing with me on that. Amusingly, after the mobs on my server were killed, they weren't respawning whatsoever. The server actually stayed up that way for about two hours, devoid of mobs, with hundreds of people standing around on Quel'Danas trying to figure out what was going on.
The instance server was up, so I had a decent amount of luck with that. We downed three of the bosses before the instance server eventually gave up the ghost, and the world server got a restart. Things were much more smooth after that, at least for my server. We didn't get the random crashes that some other servers got, which I'm thankful for. My next attempt at a Terrace run was smooth and easy, and Antiarc walked out with a Phoenix Hatchling.
The daily quests, despite it being amazingly crowded on Quel'Danas, weren't too difficult to complete. It seems the server shifted into a system of "pick a spawn point, make it your own, don't stray from there or you're fair game." Despite being stuck in one or two little areas for getting my mobs, the quests went by fast. The quests back in Outland were effortless, didn't take any time at all. Despite the server being High Population, those quests weren't camped at all. Whether that's because they're nicely spread out or because people were all crowded on Quel'Danas, I have no idea. It worked out well for me, either way.
I haven't had an opportunity to hit the 25-man yet, that'll be tomorrow night. I'm really looking forward to it, I've loved the feel of the Sunwell so far, and the difficulty of the region and all attached to it seems to have hit that sweet spot between "horribly painful/annoying" and "incredibly fun."
I'm curious how other realms are doing as far as the progression of the event. My server already has 30% of the first stage finished at 10 PM CST. That seems pretty fast compared to what the PTR was, but there's a good chance the pacing was accelerated for the live servers. How are you guys doing? Crawling along? Blazing through? About the same as I am?