I think ASM is in a tricky situation because due to the "too soon for a reboot" sentiment, I feel like it is destined to be a slow starter - that is, (if it's as good a movie as I think it will be) the WOM is what should make it a winner. However, two weeks after its opening, right when its legs from that WOM should kick in, is when the Goliath that is TDKR hits. And when ASM doesn't do much in its 3rd and 4th weekends thanks to everyone and their mom seeing TDKR, ASM's theater count will begin to dwindle, which would stop it from becoming the breakout hit it could have been if it had a different release date.
That said, it's Spider-man. The fans and kids are gonna make it a hit. Just, maybe, not as big a hit as people expect from Spidey, which would of course lead some to cry "disappointment."