I don't want to get involved in the larger view political discussion, but on an individual level, this is a hell of a deal.
Yesterday, I indirectly took part in this, as I helped my girlfriend's parents pick out and buy a new car to replace their "clunker" qualified 1 owner, 206k mile 1994 Nissan Pathfinder.
After many test drives, they walked out with a 2009 Mazda5 Touring automatic (which qualifies as a truck!??!?!), so they got $4500 for the Pathfinder (which was realistically worth $500), plus rebates from Mazda, they paid $15,200 out the door with taxes and everything (MSRP was $21,700).
They would not have bought a new car now if not for this, as the Pathy ran and drove great, and they planned on keeping it until it was really dead, but couldn't pass up the government offering them $4500 for it.