Rift had 2million accounts by the end of the first month. I'm not positive how many were there for the release, but it was far larger then who are playing SWTOR right now.
The people saying that it had 9 hour queues are cherry-picking that number. The vast majority of the servers had little to no queues. The problem was everyone picked the very first servers to roll on. And refused to reroll, even if they could regain the levels they already had in the time they would have saved from not waiting in a queue. People want to be on the most populated server though.
I'll look for some hard numbers, but I'm fairly certain i remember reading them say something in the range of 750,000 users when they opened up their last bunch of servers on release night.
Also, the website might say the release is the 20th, but anyone who has ever played a MMO before knows that the release starts the day the first character that isn't getting wiped is created. That was this morning.
Say what you will about Rift, but it is currently the most steady MMO out there. WoW is shedding Accounts in the millions right now. They officially said they lost 2 million in the last 2 years. I can only imagine what their real day to day numbers are doing.