UPDATE 1: It appears MGS1 may only be included in the Japanese version of MGS HD Collection. We're checking with Konami UK now.
UPDATE 2: According to Andriasang, in Japan, HD Edition includes HD remakes of Metal Gear Solid 2 and Metal Gear Solid 3 along with a product code for the Game Archives version of Metal Gear Solid. The version of MGS3 is Subsistence, meaning you also get the MSX versions of Metal Gear and Metal Gear 2. In total, you get MG1, MG2, MGS, MGS2 and MGS3. The HD remake of Peace Walker is sold separately in Japan.
Internationally, HD Edition includes the HD remakes of MGS2, MGS3 and Peace Walker. As with Japan, MGS3 is based off the Subsistence version, so you also get MG1 and MG2. In total, you get MG1, MG2, MGS2, MGS3, and Peace Walker. You'll have to get MGS1 on your own.
Metal Gear 1 and Metal Gear 2 are included in their original form. While the development staff was originally considering putting at least the title screens in HD, they decided to keep it retro.
ORIGINAL STORY: Hideo Kojima has taken to Twitter to announce that PSone game Metal Gear Solid is included in the Metal Gear Solid HD Collection.
"Metal Gear HD series. The domestic version is a package of MGS2 and MGS3," he wrote.
"But, there is also a product code for MGS1, and MGS3 is subsistence specification, so MG1 and MG2 which were sold on MSX are included.
"This means, you can enjoy MG1, MG2, MGS1, MGS2 and MGS3 with this one!"
We had only known about remastered versions of PlayStation 2 hits Metal Gear Solid 2: Sons of Liberty and Metal Gear Solid 3: Snake Eater, plus the PSP's MGS: Peace Walker.
A digital version of Metal Gear Solid HD Collection will launch from the PlayStation Store alongside the boxed version this November.
Meanwhile, Kojima released a picture showcasing the Trophy icons that will feature in the collection.