I've got to disagree with the initial post I'm afraid. I currently have a 17" MBP 2.4 for my own use (was a the base 15" model until I got fed up trying to find a non-yellow screen) and a 2Ghz CD MB that technically belongs to work and which goes everywhere with me.
The MBP is fantastic, a real beast and it works superbly well as a desktop replacment. So far I've found nothing to dislike about it. But the MB is the machine I'd recommend to friends and family who aren't going to be playing games or doing serious graphics work. Why? Well:
1) The MB may feel like a 'toy' but it's really well put together. I certainly feel more comfortable putting the MB in a bag and carting it Europe than I would with the MBP.
2) While I personally love the extra touches on the MBP such as the backlit keyboard most people I know wouldn't need them (not the same as wanting them of course

) and it just adds extra confusion for a newcomer to the platform (F9 and F10 being asigned to the keyboard backlight on the MBP for instance).
3) The MB has more than enough performance to do all the computng tasks you could ever wish for 90% of potential users. It's a 64 bit machine, the inbuilt graphics have got enough poke for desktop work, the hard drive is big and quick enough for most and it's got iSight built in. Wireless reception is good and the keyboard and trackpad, while not quite as good as the MBP, offer a very nice user experience indeed.
4) Heat. The MBP is fantastic and I've got no concerns about it running too hot but that metal shell does, by design, make it hotter to the touch than a MB. This goes double for situations where you're ot getting proper cooling to the machine (on a lap, in bed etc) where a lot of 'casual' users will actualy be using it.
5) Size and weight. I've got no problems with lugging around even the 17" MBP but a lot of users who carry their machine for large parts of the day (students for example) WILL notice the extra weight and size.
6) Battery life. In my experience the MB is significantly better than the MBP by about an hour (with no networking, bluetooth and the screen turned down a bit)
So basically it's a case of buying the right machine for your needs. The MBP is a fantastic piece of kit but for many people it's overkill or just not quite the right size or weight to be suited to their requirements.
All that being said, I must admit going back to the MB after this wonderful 1900 x 1200 screen does feel like someone hacked off a limb...
