get a Fujitsu Lifebook Tablet running Windows 7.
has up to the same processor as the highest level MBP, converts to tablet form, can hang from tripod legs, has 2 HDD slots - I have two SSD drives in mine.
removable battery, so you can buy extras and keep it going in the field:
yes it has firewire,
yes it has USB,
yes it has an Ultra Bright Outdoor screen.
Yes C1 Pro works on it in tablet mode.
Yes I use it with my Phase P65+ on Alpa for focus/composition,and ultra quick refresh etc.
ok its a little heavier than a netbook/ipad, but Fujitsu are selling off refurbs for $850 and up on eBay right now.
I have a T5010 there is a slightly smaller lighter model available if thats your choice.
it is the pro answer to this.