lol, its incredibly unlikely Arsenal will win the title, in which case losing to the top two teams will have been the difference to winning the title.
Had we won all 4 of those games, we've be 12 points better off, and Chelsea and Utd would each be 6 points lower than they are now.
In other words, we'd have a 10-12 point lead and be almost certain to win the title barring some swine flu outbreak that wipes out half the team for a month.
Winning isn't essential not losing is essential. If we'd won, we'd be almost 12 points ahead of both now and clear and massive favourites, if we'd drawn all 4 games, we'd still be 4 points higher, and Utd and Chelsea would be 4 points lower, so we'd again be in a decent lead.
Not losing to your closest rivals is the single most important thing you can do, anywhere in the league.