Konami just released some details about the upcoming Metal Solid HD Collection for the Vita.  Originally, the Vita version was set to be similiar to the 360 and PS3 version, meaning that MGS2, MGS3 and Peace Walker would be included.  Unfortunately, Peace Walker has been given the ax and will not be included in the Vita version.  At least you can Transfar with MGS2 and MGS3 with the PS3 version of the same game. Official press release below:

Konami announced that METAL GEAR SOLID HD Collection will become available for the new PlayStation Vita handheld entertainment system this Summer. From the critically acclaimed director, Hideo Kojima, METAL GEAR SOLID HD Collection offers two classics with vast feature upgrades catering to the new platform.

"The new PlayStation®Vita will provide fanatics with an exciting new way to enjoy METAL GEAR SOLID HD Collection," said Tomoyuki Tsuboi, President of Konami Digital Entertainment, Inc. "We're confident that gamers will be pleased with their experience and what the PlayStation®Vita has to offer with its sleek design, HD graphics and unique controls."

METAL GEAR SOLID HD Collection features two complete games, METAL GEAR SOLID 2: Sons of Liberty and METAL GEAR SOLID 3: Snake Eater. Both titles have received high accolades from nearly all major publications and websites.

The METAL GEAR SOLID HD Collection includes stunning HD graphics, optimized controls designed to take full advantage of the PlayStation Vita system touchscreen capabilities, and trophies that are shared via TRANSFARRING (save data sharing) with the PlayStation 3 system.