Up In The Air is not a bad movie, but is over-hyped and ultimately a disappointment.
The problem stems from director Jason Reitman's desire for relevance: the script kicked around for years with a different story, with the job-loss angle grafted on late in the game... and it shows. "Up In The Air" checks off the comedy and pathos boxes but lacks a coherent theme to keep the viewer engaged.
A decent rental, but as a $10/ticket Christmas blockbuster this one simply does not cut it.