Here's a great FAQ on the PSN Video Store from the PlayStation Forums:
"Q: Where can I find out what titles are available if I am not by my PS3?
A: Visit: http://store.playstation.com and click on the "Video" tab.
Q: How long will I be able to rent a movie for?
A: The content is available as a rental for 14 days. However the content can only be played for 24 hours after first playback. For details, refer to the PLAYSTATION network Terms of Service and User Agreement
Q: What defination are movies available in?
A: Video Content will play on displays ranging from standard definition to 1080p depending on the content.
Q: If I Rent a movie can I transfer it to my PSP?
A: Yes, Rental Content in standard definition format that was originally downloaded onto a PLAYSTATION®3 computer entertainment system may be transferred once by the PSN account that purchased the content to one activated PSP® (PlayStation®Portable) system during the Authorized Term. Thereafter, the Rental Content will not be available on the original PLAYSTATION®3 computer entertainment system, and no subsequent transfer to any other device including a PLAYSTATION®3 computer entertainment system or a PSP® (PlayStation®Portable) system is currently permitted. Rental Content in standard definition format that was originally downloaded onto a PSP® (PlayStation®Portable) system may be viewable on only one (1) activated PSP® (PlayStation®Portable) system during the Authorized Term. Rental Content in high definition format may be viewed on only one (1) activated PLAYSTATION®3 computer entertainment system.
Q: How does it work if I purchase a movie?
A: You may view Sold Content for an unlimited number of times on an Authorized Device. Sold Content in standard definition format that was initially downloaded onto a PLAYSTATION®3 computer entertainment system may be copied solely by the PSN account that purchased the Sold Content for use on up to three (3) activated PSP® (PlayStation®Portable) systems. Sold Content in standard definition format that was initially downloaded for a PSP® (PlayStation®Portable) system may be viewable on two (2) other activated PSP® (PlayStation®Portable) systems. Sold Content in high definition format may be viewed on only one (1) activated PLAYSTATION®3 computer entertainment system.
Q: If I purchase a movie will I be able to delete it from my HDD and download it at another time?
A: Once the Video Content has been downloaded from PSN, you will not be able to download it again for any reason without purchase of another copy.
Q: How often can I look forward to new Movie/TV Show content?"
More after the jump...
