If they make the Apple Watch Edition $1K or $5K or something expensive like that, I think all of the internals will likely be replaceable/upgradeable. Watches that expensive generally last a lifetime. In the case of smartwatches, that means the hardware will be upgraded many times. I believe the S1 will be upgradeable for about $200. They bragged about how it was a complete computer on a single chip. Not a System on a Chip, but an entire computer.