There have been whispers about a Metal Gear Solid HD Collection for a while now, propagated mostly due to the fact that it would just be effing cool to have one. PlayStation Official Magazine UK, however, has gone one step further than whisper, boldly claiming that it knows the remasters are coming.
Metal Gear Solid, Metal Gear Solid 2: Sons of Liberty and Metal Gear Solid 3: Snake Eater are all said to be in the "face-lift queue." It will join a series of HD Collections that include God of War, Sly Cooper, Tomb Raider and ICO/Shadow of the Colossus, as well as the Prince of Persia games that Ubisoft has been staggering.
I'd say that anybody with basic intuition would be able to predict an MGS collection. The HD re-releases have proven quite popular, and with Metal Gear Solid being one of the PS2's finest franchises, there's no way Konami or Sony should want to miss an opportunity. This has got to be coming.