Ratchet & Clank HD Collection was announced for Japan in Weekly Famitsu this week under the name Ratchet & Clank 1+2+3 Galaxy Strongest Gorgeous Pack. Famitsu.com has posted screens, which you can see below. As with all Famitsu.com shots, they're on the lower res side and compressed to hell, but you can still see some of the improvements over the originals.
Ratchet & Clank 1+2+3 Galaxy Strongest Gorgeous Pack will be released to retail on July 12 at price TBA. Individual download releases for the three included Ratchet & Clank games are also planned, with the first due on July 12. The others currently date TBA. Sony will also release Ratchet & Clank 4th HD exclusively as a PSN download.
(Note: These dates and release plans are for the Japanese market. For specifics on your market, wait for announcement from your local Sony.)
Ratchet & Clank
Ratchet & Clank 2
Ratchet & Clank 3