While no list has been announced by SCEA or SCEE for the Western regions, today Sony did unveil the list of PSP UMD titles that you'll be able to purchase again digitally at a discount for use on the PlayStation Vita when it arrives on store shelves in Japan next month.

The list includes plenty of titles from easy-going developers like Atlus and Nippon Ichi, however there are some very sizable gaps in the publisher catalog. Not only is this service available with only about one third of the PSP games available to download digitally on the PlayStation Store, but it seems that publishers can choose not to participate in this "deal". Titles from heavy hitters in Japan like Capcom and Square-Enix are missing completely and it's unknown if they'll ever allow their UMD titles to be downloaded from the PlayStation Store at the discounted price Sony is offering.

For now, you can check out the list of UMD Passport Program titles at Sony Japan, and cross your fingers that when this list is revealed for North America and Europe, the games you have and may want to transfer to digital copies are on it.