No no, it's quite a confusing process and I've always just missed the exploited games of PSN, but here's how I understand that it goes...
Nearly every firmware to date has had some "exploit" game, this means, say you have a vita running on firmware 3.01, then you'll need to be looking at one of the "exploit" games for that supported firmware.
This means you'll need to BUY this game of PSN and quick too, because Sony usually pulls exploited games of PSN quickly.
After you have done the exploit (this means, using a save file provided by the community which will enable the exploit in the game), you can install any PSP ISO on your Vita and play, however when Sony releases a new firmware update you'll have to make a decision, either you stick with your firmware which has your exploited game and access to all PSP games (but you lose PSN access) OR you update to the newest firmware, regain access to PSN but lose the ability to run any PSP game.
If you have a Vita running the current 3.12 firmware you'll need to wait for an exploited game to get released to the public, and if it does, get the game of PSN ASAP...
