I just played some of it, and it's good fun. Kojima & Co have really thought this one through.
The attention to detail is fantastic. I also watched this subtitled trailer with Kojima walking some Japanese journalist through some parts.
"Now you can get in the barrel and do barrel-roll attacks..."
Snake sneaks around in a barrel, then goes prone in the barrel and rolls towards two enemies, who he manages to knock out.
"Of course, after spinning in a barrel, you will feel sick to your stomach"
Snake throws up.
"You can make yourself feel better by leafing through girly magazines."
Snake flips through some pages with some hot ladies.

The resolution looked pretty nice - probably not 720p, but it did look sharp, unlike GTA IV.