Wow, with insight like that, you could work at an Apple Store ;D
Hehe... that is about the extent of their advice at the Apple Store, isn't it.
Seriously tough, as terse as it may sound (and whether or not an Apple rep could actually explain why it is), it is still sound advice. The "Power" or the "Pro" in the name is more than just a brand. Their hardware configurations/options are optimized for working with demanding applications.
The increased RAM capacity, faster processors (if only 'slightly'), bigger/faster HD choices, better graphics, larger screen/resolution, better ports/expansion, etc. all add up to a machine more suited to the sort of thing you plan on doing. For most people, the "Power" or "Pro" computers are simply overkill and never really used to their full potential.
If you're running Maya, then you will probably also use Illustrator, Photoshop and perhaps a video editor and maybe some other design apps as well. Try running all of those at once (which is at times necessary) and then render something out in Maya on a consumer machine. It'll choke. I've seen it happen many times with people who took the 'budget' route and got a MacBook (or heaven forbid, an iBook) for high-level design/animation/video work.
If you are going to be doing any 3D/animation work you need a computer with a dedicated graphics card... and the more VRAM the better. 256MB is a good amount. You will also need to bulk up your system RAM. I would suggest at least 2GB of system RAM as a starting point... more down the road is a good idea, too. You will most certainly see the advantages of these when rendering out your animations, even simple ones.
Tech is right about the notebook, you would be much better off with a desktop since they offer even greater options for customization and performance. However, since portability is a factor the MBP would be the obvious alternative.
The MBP is the best choice and the recommended machine over the MacBook for this kind of work.