This is a subjective topic of course but my personal view is that they'll
stay expensive. Mainly due to 3 reasons.
1. Low volume - it's a niche product and will always be produced in lower
numbers compared to other portables and thus more expensive to build.
2. Special technology - Touch sensitive screen, stylus, ability to turn and
fold the screen etc, all that adds to the price compared to a stock laptop.
Even if the price goes down a tablet will always be more expensive I think.
3. Portability. To succeed well a tablet need to be light, yet have a decent
sized screen (12.1" usually) and light + large equals special materials like
magnesium which drive the price up compared to regular laptops which arn't
quite as weight sensitive.
Since I can use the keyboard well I'd never stand typing any real amounts of
text using only the stylus. I love my x200t, don't get me wrong, but they
keyboard was invented for a reason and if I'd be stuck with only a stylus I'd
probably revert back to pen and paper
However, search for Microsofts Courier tablet and I think you'll find
something neat! Basically a foldable tablet with one screen on each side and
no keyboard as far as I can tell. It's a long way into the future yet and
might not even be released afaik and I'm afraid it wont be very cheap
either...nice eye candy though!