Looks like it's shaping up to be a solid device. I already have one of my games in LUA for Pico-8 (well mostly, haven't released it yet though) so I might do a port of that to Play Date once the SDK is available.
Its gonna be interesting to see how the SDK is going to be developed to make the best use of the crank.
Simulating that is also going to be an interesting design question.