Contrary to what you may have read elsewhere, Konami has not issued a 'remastered' or enhanced video of Metal Gear Solid 4: Guns of the Patriots.
GamesRadar has spoken to Konami, who informed them that the trailer which appeared on a new MGS site this morning, and which certain aggregate portals, news blogs and websites claim displays new visual effects, is definitely not new. Konami stressed to GamesRadar that it has not released any new footage, and that we won't see anything of MGS4 until E3 2007 in August.
This 'new' footage is simply a recut version of last year's E3 trailer. Smoke effects, particles, melon physics, textures - all of these things are exactly the same in both versions, with not a hint of any retouched effects to be seen. And, anyway, doesn't Konami have better things to do than fiddle around with existing footage?