Just thought you might appreciate my input here as I also deliberated over the 15" and 17" models for some time.
At work and at home I use a 24" screen (1920x1080 resolution on both), I think I would struggle to go back to a lower resolution so initially my decision was going to boil down to portability of 15" (which I could then connect to monitor) vs all-in-one of 17". I eventually decided that 17" for me, was the correct option as I wanted to move away from the desk otherwise I would have just got an iMac!
In reality, the 17" is no less portable than my old Samsung X20 15". Apart from being slightly larger in dimension my MBP is possibly even lighter, and it's just as thin! Moving around the house is not a problem. One thing to consider into your price is a good bag for transporting/commuting. I have yet to invest in a proper bag, but it is high on my priorities.
I would also recommend the anti-glare option; moving about a lot means varied levels of lighting and the matte screen performs admirably in high-glare scenarios,
Thanks for that post. It sounds like you were in the same situation as I am in now. I only have a 19" screen at work but got a 24" at home and for me to buy a laptop to plug in to the 24" would mean I should just get an iMac. I saw the C2D 17" laptop last night and was surprised at how light it was after hearing so much about how annoying and heavy it was to take out and about with you.
I'm looking in to bags at the moment, I work above a iPod/laptop accessory store so checking out what they can get.
I read on a post today that most covers/slim jackets to not provide the best cover on the corners of the laptops so that's one thing I think you might want to keep in mind when buying a cover for your's..
How well is your's performing? have you noticed any issues?