I carry both an 11" iPad Air and the 32gb iPad1 3g unlimited. I see no need for the iPad2 just yet as the 1 serves me quite well. Now why do I carry both? Because there are times for both. The iPad, in an email mode or reading mode is perfect. Sitting in a meeting and having the iPad sometimes works, but more than once, the MBA has saved me. So, as a rule, I take the MBA to meetings and use the iPad around the house, on the deck, etc. On a plane, the iPad wins for movies, etc, but the MBA rules for email and research.
I also carry a MBPro 15 for serious development using VMWare. I am a software developer and need to have that ability with me. Soooooo .... all 3 have their place and are great additions to my life.
Just my 2 bits worth.....
What do you carry all this gear in, backpack or messenger bag?