I've thought for some time that we are not really done with touch-screen text input yet. The QWERTY keyboard and its associated skills don't necessarily translate very well into the touch-screen era. Swype and its copycats do fairly well at speeding up text input, but it's still not as fast as touch typing.
This may be where double-swipe keyboards help. I've started to use one, called Keymonk, and for a while it felt very awkward, but now I'm getting used to it, and I think this might be the break I've been looking for. Initially I had some trouble with short words and punctuation, but those are common problems with any word-predicting soft keyboard. The one big difficulty I have with it is when my thumbs collide in the middle of the screen. I feel as if I haven't planned well enough, but I shouldn't need to plan how I'm going to type a word. I guess I'll get better more practice.
Check out this video of someone smashing the world record for the fastest SMS:
This is approaching physical keyboard touch typing speeds, which is what makes me think it might be the missing secret sauce. Kudos to Keymonk for a great app!
Mokalus of Borg
PS - I haven't tried yet on our Android tablet, but I know Keymonk can handle more than two-finger swipe typing.
PPS - I wonder whether eight-finger swiping is hard to learn and confusing for the keyboard.