Look. I have a white macbook (second one, not the cheapest) with 4 gb of RAM (had a great price). We've been making a ski movie with exactly a HV20. I'm using Final Cut Express, and I can say that I'm able to do maybe 80-90% of what I need to do. Basically, with the graphics card that macbooks have, you won't be able to play highly-rendered video directly in final cut (like a shot speeded up 2000%). What I do is export it and check with quicktime, and this works.
The rendering time is slower, and you won't be able to "see" as much rendered video at once as you like. However, it's enough to do the job, and if you don't want to spend an extra 600$, it's okay to go with the Blackbook.
This said, I think you have much more mac for your buck if you buy a macbook pro. For example, you have more than one firewire port, so you don't always have to import on your hard drive and THEN transfer it to your ext. hard drive, if you need to do so, you can do it directly since you have 2 firewire ports. Also, you can connect eSata to an ext. hard drive with the Expresscard, which is a freaking nice thing. Also, the video card is like the best you can get on a mac.
I personally think buying the Pro over the normal black macbook would be the best choice, but you will still be able to edit your HD footage on either computer. Hope I helped.
