Update: Make that early 2008. The official title has been changed to Rambo 4: Pearl of the Cobra.
There are numerous discussions about Stallone being too old for this, Afghanistan being anything but an adventure zone. I liked this comment in particular:
If he can do Rocky he can do Rambo. A 60 year old Ex-Vet is more believable than a 60 year old boxer.
Well, I doubt a lot of people have their expectations too high. I liked the original Rambo but the sequels were not as impressive.