Why? The pain of import. Importing from tape is a 1:1 operation - one hour of import for one hour of video. As someone used to sucking a day's worth of photography into the computer in five minutes, that just isn't tolerable. They say the best camera is the one you have with you. Well, the best video camera is the one whose output isn't a pain in the butt to deal with.
I made a little video of my office:
Office Tour from Fraser Speirs on Vimeo.
Aside: avoid the Toshiba Camileo Pro HD. At £30 more than the Kodak Zi6, I was tempted by it and bought one. The audio quality is absolutely terrible. Just don't bother.
Anyway, the joy of video cameras that use SD cards is that I might actually find time and motivation to do something with the footage. Having finally started working with iMovie '08, it strikes me what a totally fantastic application it is. Yes, it didn't quite have the same feature set as the application it replaced, but as a design for the new generation of video editors, I think it's one of the boldest and best things Apple has done in software since iLife first launched. Features can be revived (and you can see that iMovie '09 will bring some of them back, like slo-mo), but the design is fundamentally far more sound than that of iMovie '06 and earlier.
iMovie '06 was a product for a generation of amateur Spielbergs that really failed to materialise in significant numbers. It was a product of the days when we thought everyone would be making their own DVDs. The new iMovie is the product for the YouTube generation: faster, slicker, easier and more fluid.