He's 70, clearly wanted to take over a big football club for a long time now, and it seemed like United wasn't going to be up for sale for decades to come...I still don't see the point of this Chelsea argument, really isn't the gotcha that you may think it is.
I support United but if I was a 70 year old billionaire with endless money to play around with, I would have also probably put a bid in for Chelsea, knowing that the club I really want is probably impossible in my lifetime. In hindsight it wasn't impossible, of course, but no one expected that the Glazers would want out this soon.