What worries me about Amy not remembering the Daleks is that it suggests a worrying possible direction for the "space-crack" arc plot. Namely that, rather than being the jagged line it appears to be, that crack may actually more resemble a big, round, red button inscribed "RESET".
If people no longer remember the Daleks, what else don't they remember? I have a bad feeling that the intention may be to reset the in-universe Earth to match our own in terms of awareness of alien activity. I can see that appealing to the writers - makes it easier to identify with the population, discards lots of inconvenient continuity - but the concept of humanity gradually coming to terms with being part of a wider universe is an aspect of the new series that I really like, and I'd hate to see it discarded.