I've got both the iPad and the MBA 11" and I agree that the MBA 11" footprint is not much bigger than the iPad's. But, have you tried using Gmail contacts and calendar? Syncs perfectly among my two Macs, iPad and iPhone. Also give Docs To Go a shot. With that app, I can access all of my docs via Dropbox, make whatever edits I need to make, and sync with the cloud. All of the changes are automatically reflected via Dropbox across all of my machines. Works perfectly. The only real complaint I have is that the word processing and spreadsheet features aren't as robust as Microsoft Office. If they were, it could be a complete laptop replacement for my uses.
Thanks so much for the tips. Perhaps I'm old fashioned, but I'm still leery about moving everything to the cloud. There have been a handful of times it's been hard for me to access WiFi or a 3G signal. I want to know that the information I want is with me and the iPad's file system seems to leave a few things to be desired. Nevertheless, my colleague uses DropBox and has never had problems. Maybe I should give it a shot.
As for Google, I do have some confidential data and I'm again leery about using something where terms and conditions may change. At work, we use Outlook so ideally I would find something that syncs well with that.
Thanks again for the info!