The Touchstream takes getting used to - after 6 weeks with the layout adjustment and the new keyboard, I'm only at 65 wpm, where I used to be at 105 on qwerty. BUT, mousing on the keyboard surface and gesturing, rather than doing key combos saves a lot of time (not enough to make up for the typing yet, but getting there). To cut, you highlight the text and pinch your fingers on the keyboard. To paste, spread them apart. Close windows with a twist. I can have a gesture for any keyboard combo.
Another cool feature about this keyboard is that gestures and modifications are saved to firmware, which is updated by a Java application. I don't have to worry about the software getting killed by platform migrations (like the move from PPC to Intel).
The Engadget article refers to tactile feedback which already exists on the keyboard. It seems to work by monitoring the amount of surface area that your finger is using and whether that amount is increasing or decreasing (for say higher key repeat rates and such).
Unfortunately, after Apple purchased Fingerworks, they stopped selling keyboards, and worked on integrating the technology into the iPhone and probably the next generation ultralight. To find one, you have to ebay it(where you might find one for 600 bucks), or, occasionally, they show up on Craigslist(where my friend lucked out and found someone getting rid of one for $50).
