As a newer MacBook owner, I totally appreciate you posting that link: I'd heard about the article, but didn't get a chance to read it. I've got the pair of 1gb chips in mine, deciding against the single 1gb and single 2gb. Of course, the graphics in the MacBook are not as beefy as the MB Pro. I haven't been using mine for PTLE, but have been doing a lot of video editing and processing, and it's worked out very well.
I always refer back to my older PTLE setup: 6.1.2 on Windows xp home, 1gb ram, 1.8GHz AMD, and I believe 333 bus, and I never ran out of track availability. I have a hard time believing that the MacBook Pro would bog down with 2gb ram and a bigger bus. I could totally understand more ram if you were running simultaneous programs with a virtual sampler or something (stuff that's just beyond me now, so I'm typing from a naive point of view), or maxed out track counts with maxed out plugins.
The second article makes me drool a bit

. To me, those specs make the whole discussion moot...go with the newer Mac Book Pro and max out at 4gb of memory. With that much memory, the bigger bus, and that processor, I can't imagine that it wouldn't perform. Just make sure the audio processing program(s) are compatible.
This isn't necessarily true anymore, I will post a link to the article that I read concerning exactly this.
Is 3GB better than 2GB of RAM? Yes and no.
and also
New MacBook Pros: the full 4GB, LED backlighting, 2.2/2.4GHz