The Ratchet & Clank Collection will be available on August 28th on Blu-ray and PlayStation Network. For $29.99, you'll get 1080p HD remastered versions of Ratchet & Clank, Going Commando, and Up Your Arsenal. In addition to the games, the collection will also include first access to the Sly Cooper: Thieves in Time demo. There's also a bonus PSN avatar for you to use.
If you're only interested in the Sly demo, don't fret. You'll be able to get the demo without the Collection. "But this is the only way to get it early," the PlayStation.Blog notes.
If you don't want to pick up all three games at once, you'll also be able to buy them individually on the PlayStation Store.