The MBP keyboard is excellent but I use a BT keyboard so that I can keep the lid closed and have more desk space.
I am selling my G5 Desktop and doing everything with my 15 inch MBP. The only drawback I see is that I am limited to 120 GBs for the internal drive. I have 250 GBs for applications and 250 GBs for data on separate drives and internally on my Powermac G5. I found workarounds for storing my Garageband libaries separately, using Parallels for Windows instead of Bootcamp, and moving iTunes and iPhoto libaries to external drives. iMovie is still a problem because I can't find a Firewire drive that can keep up with capturing video. I have to move to eSATA drives for iMovie. I don't know if FW800 will work but I don't have FW800 on the 15 inch MBP. For now, I am limit my iMovies to about an hour of video per project. I use EyeTV and those videos are small and I archive them if I want to keep the shows.
I use the Apple 30 inch display and keep my MBP screen closed and use a Apple Bluetooth keyboard and the new Mighty Mouse that I really like. Gaming has been excellent and I use the old USB Apple Soundsticks for my audio.
I envy your MBP 17 because of the extra FW800 port and extra USB port. You can never have enough USB ports. I could expand my desktop to include the 15 inch display in addition to my 30 inch display but I feel the 30 inch display is easier to work with by itself.
I wish I could have more than 2 GBs of memory on my MBP. On my Powermac, I could easily have 8 operating systems or more running at the same time with Virtual PC. For example, run SQL Server in one instance of XP and Oracle in another instance with Linux. I had the disk, memory, and screen space to do everything I ever wanted on my Powermac. (Just wish I could run Windows natively). I had a really good system for Motion and Final Cut Pro if I had those products.