From reports, it seems that the versions of the games on PSN are not the same as the original PS2 versions from a data standpoint. The save games for example are completely separate from the PS2 versions, being substantially different in size and also saving as its own file rather than being part of the PS2 memory card utility, and they also claim that each title requires "special development" to get working on the system. It doesn't sound like it's actually using an emulator from this (at least it isn't using the PS2 memory card emulation that was already done in software even on backwards compatible PS3 systems), although I'm interested in hearing exactly how it works either way.
Also, the "HDMI shutdown" happens whenever there's a resolution change, it's not dependant on the type of program running.
"Walking tanks must exist somewhere for there to be such attention to detail like this in mech sim." - IGN Steel Battalion review