There have been over 540k online registrations since they started it. That's a 3% registration increase. Registration had only increased by 300k in the first 9 months of the year prior to that.
1. Many of the applications are registration updates, so they aren't all new voters.
2. It's likely that a higher percentage are invalid than normal, as registering fraudulently is easier.
3. In the last 45 days, registration went up around 300k in 2010 and by 1.1 million in 2008. So a registration jump is normal.
This has the potential to be painful to one party or the other. Word is that Democrats are benefitting heavily, but the SoS has yet to confirm that. These reports frequently don't go up for several weeks after the deadline date, so accurate counts might not be available before the election.