Hard to do a projection off of 6 weeks of data. Also, a year ago I didn't think AC had a chance of outselling Pokemon, so I really don't have a good sense of how popular AC really is other than my daughter and several of her friends have the game. I went ahead and voted 40m+, because AC ususally has really good legs and this is on a system where it's now common for titles to smash sales expectations.
As for bugs, I didn't even know this was an issue. The only issue I was aware of was the whole 1 island per system thing.