Well, tried the application number on the picture to the US Patent office search and it did show the patent MOBILE COMMUNICATION TERMINAL WITH A SINGLE ROW KEYPAD with assignee NOKIA CORPORATION. So clearly it is Nokia applying for it and to me it seems fine idea.

Personally I'd rather have full keyboard, but for some people that will probably be nice option, and it would be nice to have different Maemo devices for different people and purposes, so I'm all for it!

It actually looks similar to the Sony eReader I bought for wife. That one has number buttons at the side as well.