Hand Held Hollywood has a short video demonstrating the upcoming 1st Video editor from Vericorder. The video demos creating an assemble edit, trimming clips, adjusting the audio volume and even adding an audio fade out. That app gives great demo! Unfortunately, they didn't show (or ask about) transitions or titling.
It's really very impressive; though I'm tempted to wonder how much I should get invested in editing on the iPhone....also, I wonder what resolution video the next iPhone will capture at, and will I have to buy the app all over again to support higher resolution?! [their website talks about a "pro" version that will edit HD video]
1st Video should be out soon - according to the developer it's all in Apple's hands - and will have an introductory price of about $10. Looks cool.