I think it's a great move. Not everyone who wishes to serve their country wants to join the military, and this provides another viable option — one that, like the military, provides higher education incentives.
It's also a boost to the economy, one creating jobs for everyone from high school graduates to seniors. If I were a recent college graduate who couldn't find a job in my field, I'd definitely look into AmeriCorps.
I also dig the message of volunteerism the bill sends — let's help our fellow man instead of shooting at him.