Now, you will be able to download the free-to-play game from the PS Store, and play for as long as you want up to Level 15. Upon reaching level 15, you can choose to raise your level cap to 25 or remove the cap using microtransactions which will bring your level cap to 75, and it will also include all the legacy goodies.
The Co-op Arena and select modes are not included, and must be purchased. You can get the full list of what is free and what will cost you through the PS Blog.
Pricing wasn't noted on the blog, but doing a search, we found Joystiq was given an preliminary pricing model.
To date, over 3.5 million people have played in over 37 million matches and over half a million players actively play Uncharted 3 each month.