Installed the Vudu player on my PS3 (USA only). Haven't watched a feature film yet, but checked out a few trailers. The video quality is pretty amazing (that's Vudu's selling point), and the selection of movies is incredible (Vudu's second selling point). The drawback is it's isn't a buffet-style all you can eat offering; it is pay per view.
The pricing is staggered by video quality SD being less than HD, and HD being less than HDX (1080p/5.1 DD+). The normal pricing is $3.99/$4.99/$5.99 respectively for new releases, older titles can be less. There's also a section called "$2 for 2 days" (to compete with Redbox) that's priced as: $2/$2.99/$3.99. Also every day there's one title selected to be $0.99 across the board (today's is The Miracle Worker, but HP: The Order of the Phoenix was just the other day, so the selection seems to be pretty eclectic.
The player is in the Playstion Store on the New Release page for now, and will always be found in the Media section. Installing it gets an automatic $5.99 credit applied to your account (expires on Christmas). You have to go to vudu.com to add a credit card, as there's no way to do it from the player interface.