iMovie is quite a let down. Here I thought that iMovie was going to give ReelDirector a run for its money. So far, ReelDirector is the most intuitive and flexible video editor i have seen for the iPhone, which has been on the market since last October...even though it doesn't support fancy looking (and useless) themes. ReelDirector does some nice titles, transitions, trims, music + video audio combinations, pictures, etc. etc.
If you look past all the counter intuitive interface, the most annoying part of iMovie is the titling. Why must I have a bottom title that lasts the duration of the clip it was applied to? Any normal video editor will give you the option to fade it away after a few seconds.
The only features i like? Themes (if they ever end up being useful), real time video rendering (ReelDirector needs to render), bottom scrolling clip editor.