I crave this too, mainly to replace failing parts at first but will probably get hooked and go full chrome junkie :D

There's some pretty impressive arm prosthesis now, I would expect those to be close to original by the end of the decade, without significant retraining required when coupled with an ai network and feedback based on mutual information (there was a recent paper on this by one of the AI labs, not specifically prosthesis but learned interfaces, I can't find it at the moment :S).

The BCI required for full cyborg is probably 15-20 years away, and full organ replacement, no idea, I haven't heart much apart from artificial hearts.