BT Games' website. As Digital Spy notes, the retailer had a January 2012 release date on the fuller page (since removed), but that date could have been a placeholder. Sony has yet to confirm a Jak and Daxter collection.
An HD collection would likely include the three core entries in the Jak series, perhaps with kart racer Jak X as a bonus. Hm, we're probably using the word "bonus" there incorrectly, but let's roll with it.