Some History: If my record keeping is correct, iDVD 7 was released in 2007 as a component of the iLife '08 suite of applications. Since then it has been updated numerous times, most recently in July 2011, to make it more compatible with iLife '11 and Snow Leopard. Apple no longer sells iDVD, but Amazon.com still has copies for sale.
Despite the numerous updates, iDVD has gotten creakier and creakier over the years, especially when running under Lion. Sometimes menus don't display properly. Sometimes menus don't respond to "move highlight" commands in a logical way. DVDs are still limited to two hours in length. The application is just plain slow.
Will iDVD keep working under Mountain Lion? Who knows?
Time To Replace iDVD: I started shopping around for an iDVD replacement, starting at MacUpdate.com and ending up at the Mac App Store. The App Store has a number of "DVD Creator" applications that all look about the same and whose developers are all named in Macworld's list of companies to avoid <http://www.macworld.com/article/1153685/speaking_spammers.html>. Ignoring this sound advice, I purchased Xilisoft DVD Creator 7, the highest rated of the lot (3.5 out of 5 stars), and at the time, discounted to a quarter of its regular price.
Upon downloading, I was presented with a new icon in my Applications folder, Xilisoft DVD Creator 6. SIX?! Launching the app and checking "About Xilisoft DVD Creator 6" revealed that I was in fact running Xilisoft DVD Creator 7.0.2 build-1221. Clue-By-Four #1.
Time to create a DVD: I had several 16:9 aspect ratio video clips in various formats, and I dragged them into that app's main window. It accepted all of them, something iDVD can be fussy about. Next I needed to choose a menu template. The app contains forty-two non-animated templates in three general categories. It's possible to enter a main title and give titles to each clip, though the filenames of the clips are not carried over into the template. Fonts and text color are also editable. (I discovered this feature quite by accident. There isn't much documentation.) The Font menu displays in WYSIWYG format, a nice feature.
I selected the 16:9 radio button and Full Screen from the Zoom popup, Save as Image from the Destination popup, and clicked the Burn button. There is no comparison how fast this app is compared to iDVD. Let's just say it's a lot faster.
I could have burned directly to a DVD or saved to a DVD folder, but for starters I used Disk Utility to burn my image file to disc. I took my new DVD out to the living room to play it through the DVD player connected to the TV.
The menus did not display correctly! The TV image was at the proper 16:9 aspect ratio, but the highlights, the areas telling where you are in the menu, seemed to be at 4:3, creating a very ugly look. What's more, the highlight for the paging arrows was completely off the bottom of the screen!
I gave up after five iterations trying to find a magic setting that would produce a 16:9 aspect ratio DVD whose menus would display properly when played on a regular DVD player. Strangely, these DVDs display their menus correctly on my Mac's screen. Too bad that's not where I watch DVDs. iDVD understands aspect ratios, and always produces discs that display correctly on any player. Clue-By-Four #2.
If you already have a recent version of iDVD, you're going to be very disappointed with this app. It's one and only advantage is that it's a lot faster than iDVD, but it falls short nearly everywhere else.