I am actually doing a lot of shifting.
1. 64GB WiFi + 3G. This will be replacing my Kindle DX and will be my new portable, replacing my Air. I will be developing in house apps to perform the functions I normally would on my air.
2. 16GB/32GB WiFi (maybe 3G). This will be replacing my fiancee's Kindle. I will be shifting my Air to her and taking her Uni Macbook classic as my new test/development machine. This iPad will also be the living room pad for other functions.
Like you, I'll be getting rid of my DX and my wife's K2. Haven't decided which way to go about the iPad.