ESRB Watch: Tekken, Front Mission 3, Metal Slug X
The ESRB website is currently listing PSone titles Tekken, Front Mission 3, and Metal Slug X for PS3/PSP, indicating they may be coming soon as PSone Classic titles on the Playstation Network.
Tekken was one of the earliest 3D fighting games to appear on a console in 1995. Front Mission 3 is a turn-based, mech-themed RPG that has already been released on the EU PSN. Metal Slug X is a revised edition of Metal Slug 2, originally released in 1999.
Release dates for these titles have yet to be announced. Look for them in a future store update on the site.