The exploit will be available for the US/EU/JP PSN Stores, although 173210 has asked for donations so he can buy the EU/US versions of the game to work on a port.
173210 has not given any additional details, but as always this exploit release will require you to purchase the (yet to be announced) exploited PSP game on the PSN, and install that game on your PS Vita. You will then be able to trigger the exploit through a savegame file that will be released by the hackers.
In general, once such an exploit is announced, Sony tend to remove the exploitable game from their store within a couple days, if not a few hours. So you’ll have to act quickly when the exploited game is announced, in order to buy it before it gets pulled from the store.
It is safe to assume the exploit will run on the latest PS Vita firmware 3.55, and should let you run ARK, TN-V, and the same collection of hacks available these days. ARK and TN-V let you run homebrews, plugins, and PSP isos on your PS Vita. These system do not let you run any native PS Vita homebrew, let alone Pirate PS Vita games.