While it's not as laugh out loud funny as the I'm a Mac, I'm a PC adds there are some moments. Like when Gates holds up his Shoe Circus Clown Card and his photo is his mug shot photo! Steve Jobs would never be so self deprecating or get caught speeding in a Porch 911.
TechCrunch has a good article on the subject and cites an internal Microsoft email that mentions that this is only the first in a series of adds that will reintroduce people to Microsoft.
I know everyone is totally dumping on this add, but lets wait till be see the whole campaign before we torpedo it.