As an extension to what I mentioned earlier about DBUS access I should also clarify that any apps that use the existing notification system on the N9 will have their messages sent to the Pebble automatically without the devs needing to do anything extra.

Gesture stuff could be very exciting; personally I'd be quite interested in writing a few games that use the Pebble as a motion controller. Unfortunately the Pebble app SDK still doesn't allow access to the accelerometer data. I hope we won't have to wait too much longer for this, as it's a shame to have the functionality available in the hardware but not be able to make use of it.