While it would be great for business (we make Bluetooth keyboards for BlackBerry's) personally I hope they don't.
I have had all sorts of smartphones with touchscreens and played with most of the latest ones but have to say nothing has been able to compete with my old curve and now my bold for ease of text entry.
As already mentioned though if BlackBerry made a touch screen device with a high res screen and a slide out keyboard I would be the first in line to buy it