yeah, I had a 2010 MBP through my last job; when I left, I had to give it back. Instead of getting another MBP, I went with the 2011 iMac. I had the same thought that the MBP would be more portable etc., but honestly I haven't really needed/missed the portability of the MBP. The iMac has a bigger screen and is just... sexy.
Plus the iPad has definitely fulfilled my mobile needs. And the 1 time I've NEEDED the computer in another room, the iMac was plenty easy enough to move. 
I never got the "iphone does what the ipad does" argument.
Yeah, ok... on 3.5" of screen. I'd much MUCH rather browse the web/check email/watch video/play mobile games/show off photos/etc etc on 9.7", period. The iPhone is great in a pinch, but if I have a choice, I'll take the iPad all day long. It leaves the house with me and is always available if needed.
Same philosophy at work: I was offered a laptop with 3G, or a desktop and an iPad 2 with 3G. I took the latter. I hate carrying around bulky laptops.
My
house:
iMac - Me
iPad 2 3G - Me (work provided)
iPhone x2 - Wife, Me
iPod Touch x2 - Middle daughter, youngest son
iPad 1 wifi - oldest daughter
2007 MacBook configured as home server
Apple TV (I want one for every TV now)
Girls also have PCs and wife has aforementioned PC, but they'd be macs if I could afford it. I'll replace my wife's laptop with either an iPad or a MBA.
I never got the "iphone does what the ipad does" argument.
Same philosophy at work: I was offered a laptop with 3G, or a desktop and an iPad 2 with 3G. I took the latter. I hate carrying around bulky laptops.
My

iMac - Me
iPad 2 3G - Me (work provided)
iPhone x2 - Wife, Me
iPod Touch x2 - Middle daughter, youngest son
iPad 1 wifi - oldest daughter
2007 MacBook configured as home server
Apple TV (I want one for every TV now)
Girls also have PCs and wife has aforementioned PC, but they'd be macs if I could afford it. I'll replace my wife's laptop with either an iPad or a MBA.