I went with the 16GB 1st-gen iPad, and ran into space limitations. For the iPad 2 I went with the 64GB version with no problems, typically I'm under 50GB. Now for the retina iPad, it seems that my high quality apps will be GB hogs and may result in managing apps. It would be nice to have a method to see the last time each iPad app was launched to determine the best ones to remove and open up space on the iPad.
I will keep you informed as this plays out...may need to up my space in iCloud!