Now, iMovie HD 6 can be downloaded from Apple's website if you want those effects again. All you have to do is export the movie from '08 and drag it into HD 6, where you can add your chapter markers and effects. If you want to edit sound and music, that's what GarageBand was made for - audio. You can still export it as a movie in GarageBand. However, if you want to export to iDVD, then you better download iMovie HD 6.
Apple's iLife focus seems to only be on iPhoto, iMovie, iTunes, GarageBand, and iWeb (iWeb mostly for marketing purposes with .Mac). It looks like Apple's doing one of those one-big-jump-per-decade thing again. It was making computing personal in 1977, taking away the command-line in 1983, and taking away the floppy in 1998. Is Apple moving away from the DVD this decade? That topic's worthy of its own blog post. Stick around!
Oh, by the way, what are your thoughts on iMovie '08's simplicities? Do you think it's not really "simplified" like the way I explained it, or do you think you'd rather want something all-in-one instead of splitting up the tasks into various apps?