The US online store for Sony's PlayStation Vita has already come online with a number of downloadable titles, but one question that has remained open is exactly which PSP games will be compatible with the new device. The company provided an answer today, posting a preliminary list of 275 downloadable games that will be waiting for gamers, including Final Fantasy IV: The Complete Collection and Tekken 6. Alternative methods to get PSP games onto your Vita are also covered — if you've got compatible titles on your PlayStation3, you can copy them over via USB — but there are limitations to how many devices games can be activated on. Joystiq also reports that several additional titles work with the device as well (Valkyria Chronicles 2 and Pixeljunk Monsters Deluxe are cited), with Sony noting that its master list will be updated in the coming weeks. It remains to be seen whether the expanded catalog will help the Vita avoid the sales issues it's had overseas, but we'll know when the device launches on February 22nd.