To add to the reports, we just got back, and rode Hagrid's twice. The first time, Saturday night, we got in line five minutes before park close, which was at 10pm. We waited about 25 minutes, including child swap and the preshow. The following days they seemed to close the Hagrid's line no later than 9pm. Our last day, we got up at 5:30AM and were on the first boat to leave the Portofino at 6, got to IOA entrance at 6:15. Waited until 6:45 for them to open the gates and scan our tickets, and jogged all the way to the back of the park. We didn't need lockers so we walked right onto the ride, no preshow, and were the last pair admitted before they started using the zig zag queue right before the loading area. When we got off the ride it was 7:15 AM and the ride was already posting a 180 minute wait, and the queue was filling up out to the locker area. Quite regularly this past week the line was posting 250 minute waits by 7:30 AM. I can't imagine showing up to the parks and immediately spending 3+ hours in line, but a lot of folks seemed happy to do so. After we got off Hagrid's we grabbed a Pumpkin Pasty at Honeydukes and did a bit off shopping in Hogsmeade, then went to Velocicoaster and waited about 15-20 minutes, including getting our shopping bag into a locker.
While we loved Velocicoaster more and rode it 3 times over the course of our trip, Hagrid's is also really special. But getting there an hour before early entry or right before the shut down the line seems to be the only way to avoid a multi-hour wait. I never saw it drop to less than 120 minutes during the day or early evening the whole time we were there.