I tried it one hour ago in Indigo (Montreal downtown) and I will share my personal view:
Design: Very nice piece. I read some comment about the switch on/off and the central button. For me everything seems good. Also the device is light and feels good in the hand.
Reading: There was 2 fonts, I prefer the serif one. The touching was not really responsive and I was quite surprised because I have a PRS-700 and it was as responsive as the demo unit (I've handled 3 demo units).
The dictionary function was not easy to activate as you need to highlight a word and not simply touch it.
Library: It does the job. You have a view with one book per page, it would be great to have a summary of the book when in this view, perhaps in the future...
To be noted, I think it really clever to have the different books you are currently reading on the homepage.
Store, Reading Life : That was really the annoying part. You couldn't access the wifi because it needed a key on the demo with a library and you couldn't touch anything with the 2 others because they hadn't been sync yet. So much for a trial then.
In resume, I spent some time in both boards (Kobo & Nook) and was eager to try the Kobo Touch as soon as I heard the announcement. After what I saw today, I know for sure I won't buy it before they arrange a lot of things in their OS.
As I live in Canada, I have not tried the Nook yet but for what I saw on reviews, it seems a more reliable product so far but to be honest, I still love my 700 so maybe I'm not quite ready for a trade off