Well I think Arsenal can and will go again, but you're correct about pundits having a short memory, as if City will suddenly forget everything they've done to win 4 PLs on the bounce and start to crumble! Isn't gonna happen. City are the team in possession and it will take an almighty effort to overhaul them. I think when Liverpool did it they win pretty much all their matches for the 1st half of the season. Might take something like that.
As an aside, Arsenal's transfer policy over the last 12 months seems to be based on signing tall players with exceptional hair. Someone pointed out on an Arsenal group that Iniesta kept Arteta out of the Spain national side and that Arteta is compensating by signing only tall players with great hair!!!