Comment My conditions (Score 1) 427
Well first of all the usual stuff. It needs to be completely open source and have an open bootloader so there is a chance of security. It also needs to have rather simple code so it can be checked, as well as decent battery life.
Then there is the whole issue of user interfaces which isn't even solved for mobile phones these days. What you need is a powerful interface that works on small devices. So far the best contestant in that area seems to be the HP-01 calculator watch.
http://www.led-forever.com/htm...
It allows you to start a stop watch, and then use the result in real time to do calculations on it.
Unfortunately it seems like "smartwatch" manufacturers will go the other route, making them rather useless. Just like they already did with the idea of a "smartphone" when they turned it from something like the Nokia Communicator to something like the iPhone.