In this year's season opener United played better than the two teams that finished above them last year.
They certainly have a stronger squad than Arsenal. United solved their goalkeeper problem by bringing in EVDS and added an explosive winger to push Ronaldo and Giggsy for places, all without losing any first team players. Arsenal on the other hand lost their second best player and haven't found a suitable replacement. Without Thierry Henry Arsenal would have a weaker squad than Spurs.
First place will be a challenge, but United should finish second and hopefully pick up another trophy. Chelsea scraped a win against Wigan, hopefully that's a sign of things to come.