In the past, you used the Apple TV's Movies entry to view trailers--top movies for sale on the iTunes Store or general theatrical trailers--and access movies stored on the Apple TV or streamed from a computer's iTunes library. The new movies entry includes these options as well as the means for previewing and renting movies from the iTunes Store (you can't purchase movies from the iTunes Store with the Apple TV).
When you choose Top Movies you'll see a screen filled with movie posters. The top row includes featured films. The rows below show Top Rentals (25 entries), Just Added (28 entries), Staff Favorites (18 entries), and a row of movies specific to a particular genre. When I was using my Apple TV, this row held 17 westerns.
To navigate to a movie, just use the Apple Remote to move up, down, left, or right. When you select a movie, its title is shown below. Click a selected movie and you'll see an information page where you the movie poster at a larger size, a plot description, movie details (release date, length, actors, director, and producers), a Preview button, and options for renting the movie. Standard definition versions of movies are available for $3.99. If an HD version is available it will cost $4.99. Many, but not all, HD versions include a Dolby Digital 5.1 soundtrack, which the Apple TV is now capable of playing. At the bottom of this screen you'll see a Viewers Also Rented area that displays movie posters for films that others renters of that particular film have also rented.
To rent a movie, just choose a rental option (standard or HD) and press the Remote's Play/Pause button. If this is the first time you've used your Apple TV to purchase or rent something, you'll be prompted for your Apple ID and password. After you've entered them you'll be offered the option to save this information so you don't have to enter it again (you can delete this information within the iTunes Store area of the General setting by choosing the Sign Out command). This is helpful, as the Apple Remote isn't the most flexible input device on the planet and the less time you spend choosing a letter, navigating to the next, and on and on, the happier you'll be.
Just as with movies you rent directly from the iTunes Store with your computer, you have 30 days to begin watching the movie and then 24 hours to complete watching it once you've started it. (Bonus feature: If you've already rented something, the Apple TV will tell you so and ask if you're sure you want to rent it again.)
Once you've agreed to rent a movie, it begins downloading to the Apple TV. A Rented Movies screen appears that displays the poster of the movie you're renting. Below that movie is its title along with a progress entry that tells you how far along the download is (by percentage of movie downloaded). While the movie download you can press the Menu button to back up through the interface to use other parts of the Apple TV. When enough of the movie has downloaded so that you can watch it without interruption, an alert will appear on your TV screen.
I rented the HD version of Live Free or Die Hard and 12 minutes after initiating the download, I was told that I could begin watching it. Once a rental is ready to watch, a Rented Movies entry appears in the main interface when you select the Movies category.
The Movies entry also offers ways to search the iTunes Store for rentals. Among them you'll find a Genres command for viewing movies for rent by genre (G, PG, Action & Adventure, Comedy, etc). You can also choose an All HD command to see just movies offered in high-def. Choose Search and you can use the Remote to enter letters to search for the movie titles you seek. It's clumsy, but no clumsier than doing the same kind of thing on a TiVo.
This Apple TV's Trailers entry shows only theatrical trailers for movies playing today in movie theaters. (If you want to see trailers for movies available from the iTunes Store, you do so from within a particular movie's information screen.) Within Trailers you can choose to view just HD trailers or choose all available trailers by title.
The last two entries, My Movies and Shared Movies, bear some explanation. With the original Apple TV you had to choose from among your media sources--media stored on the Apple TV or media stored on synced and streaming computers. Apple has simplified this by creating these two entries. The first, My Movies, is for movies you own that are stored on the Apple TV's hard drive or are on the computer the Apple TV is synced with. Rental movies don't appear here but rather in their own Rented Movies entry. When you select Shared Movies you'll see those movies available on computers connected to the Apple TV for streaming. These My and Shared entries are also found under the TV Shows and Music headings and work the same way--My media is for media stored on the Apple or synced computer and Shared media is for media that's being streamed to the Apple TV.