There's one thing that bothers me...
Let's say you bought this watch, partly for it's "fitness tracking" abilities. Would you still wear your Omega occasionally? If so, you'd lose that day's tracking info. Wouldn't it be slightly annoying?
This is only one example. The same goes with the other essential functions of Apple Watch. At some point in the future, you'd be so spoiled by it's capabilities (in conjunction with the iPhone 6/Plus) that you'd stop wearing the old good mechanical watch completely.
I have the impression, that this could be the reason why "Swiss should be afraid" in the long run indeed.

Please excuse my grammar...