If they could incorporate a heart rate monitor and GPS then this would be my ideal workout companion, and I could use it for bike rides and snowboarding in the winter - the separate costs of all these would be more than $300. I don't think it will become mass market, BUT you can only make the watch so small after which the interface become unusable - esp if you have fat fingers like me! You do require the the revolution before the evolution though, like with the Google Glass hopefully.

But regardless of the size of this, have you been to a watch shop recently? Some of the sizes of the watches are ridiculous and I presume they sell... so this might do just fine!