I don't know. I sorta disagree with you guys. I own a 13" MBP, now watch as I shamelessly defend my purchase.
I definitely agree that the 13" is not a workstation, but I still believe that the 13" MBP has pro features that set itself apart from the Macbook.
I realize what you're getting at here, and comparatively speaking, the MBP is a better system than the MB.
But it's not built for professional use in terms of rugged reliability @ 100% core usage across all cores, HDD running full tilt,... (99.9% availability in a 24/7 environment). Laptops are a much harsher environment to provide adequate cooling,... for that level of reliability, not to mention it can be damaged from being dropped (the MP doesn't sit in a users lap; at least I hope not
).
For one, the firewire port allows me to run my firewire audio device for my work, something I can't do with the Macbook or the Air, for that matter. Also, the ability to expand the RAM to 8 GB also allows me to work seriously in Logic Studio. Again, I cannot really hope to achieve this with the Macbook.
In this respect, it's a better choice for on-site work. I've known a few that record their camera output directly to the laptop, then upload the files to the MP, and do the heavy work there.
So in a sense, it can be called "Pro". But they could have come up with another way of selling it IMO that indicates what it does without the inference of the reliability levels of a workstation (which it's not capable of). A simple name change could have sufficed.
It may not have discreet graphics, but as my example points out, not every pro user is in the graphics or animation field.
Laptops tend to have fixed graphics, so I see that as part of the compromise for portability. They're not meant to be used as a 3D animation system.
As for the desktop line, the biggest differences are expandability, the massive cap on RAM, and incredible number of cores that it can go up to.
You can almost compare the differences between the quad Mac Pro/i7 iMac to the Macbook/13" MBP.
Workstations are meant to be reliable though, and is one of the biggest selling points. Oddly enough, this expectation is so ubiquitous, that it's not mentioned in sales/marketing literature as the name
Xeon denotes this aspect of the system. Simply put, reliability/availability is synonymous with the moniker. So it gets focused on features such as those that have already been mentioned during this discussion.
That's why "Pro" has the same consideration with the MP, as it's a Workstation and uses Xeon processors. That may not have been Apple's intent, but it happened due to the workstation/server environment as a whole IMO.
