I wouldn't jump to conclusions after one game, although City and Chelsea look ominous.
City have the pedigree and that aura/confidence that serial winners develop. They have a core group of players who have won two titles and been in the mix for 3-4 years now. They won it last season after Chelsea and Liverpool stumbled and it will take another team being consistently very good from start to finish to have any chance of beating them. No other team has proved they can do that. Chelsea need key players fit and in form throughout the season in my view. They don't have anyone who can pass and control play like Fabregas. Costa needs to be the 20 goal striker they've been missing. How good is the defence if Terry and Cahill miss a number of games?
Arsenal have a lot of good players, but it's a number of years since they got decent results against the other top sides. Are they good enough? Are they still vulnerable at the back and a bit too lightweight throughout? Replacing Vermaelen with Chambers is one for the future, not now. Flamini is no Vieira in midfield.
Ditto Liverpool. Suarez carried them whatever their fans might say. No team wins the title with a defence which concedes 50 goals - and so it proved. Can the defence really improve by the 15-20 goals required?
Spurs and Everton may challenge for top four but look the 5th and 6th best teams to me.
Utd need to spend money on quality players in a number of positions quickly. But LVG won't spend it for the sake of it - and until he does Utd look weak at the back and hit and miss everywhere else. 7th last season, with champion players still in the team, means that 7th without many of them looks to be the best achievable. The cloak of invincibility has long gone. There isn't a quick fix; getting back in the CL would be a small step in the right direction, but that looks a long way off at present.