I am apparently the last person on earth who does not yet have an iPad. Anyway, those that have them are using them for video editing, as described here: Quick-edit Videography with iMovie for iPad « Moving at the Speed of Creativity.
Me, I still use my MacBook for portable work. Why? I like having over 100 Gigabytes of disk storage available, plus an external disk drive as well. I store stills and video on board while traveling.
For event videography, I sometimes record direct to disk, routing the Canon XH A1’s firewire output direct to the Macbook. This copies the HDV equivalent files to the disk, for captureless editing. At 12 to 13 GB per hours, this uses up considerable disk space rather quickly!
- Quick-edit Videography with iMovie for iPad (speedofcreativity.org)