Groundbreaking news:
The Apple watch is not thick, when compared to other mechanical watches that are also the same or similar thickness.
I think we all know the Apple watch is as thick as it is, as it needs to be that thick to fit in what Apple wanted to fit in with the tech they had to hand, when they started planning the device, which was probably a year+ ago.
Mechanical watches are mostly, all make thick for style reasons, not because they have to be that thick.
We all know we HATE thick generally, Apple hates thick.
With every generation of every Apple product they have worked really hard to make their devices thinner and thinner.
I have no reason to doubt this will be exactly the same journey the Apple watch will take. Perhaps in 5 years time, it will be down to perhaps half it's current thickness, and we will all go, ohhh wow, amazing.
The issue is going to be WHAT will we consider, as time goes on to be an acceptable battery life?
We have pretty much accepted that a Phone will last a day with normal usage, perhaps 2 days if you hardly use it at all.
That's just established itself as an accepted amount.
Perhaps the same timeframe will also be expected of a watch, or perhaps the watch will be expected to have a longer life.
Apple, will as always juggle the thinness of the device, and keep the battery life to the same acceptable amount, whatever that turns out to be in time.
I would also expect, over time the Apple watch, like the iPad, become more independent a device than it is right now.
People would obviously like it to be able to do more without the phone being carried at the same time. And that will come also in time I'm sure.
It just takes time
Think of this as iPhone1 and think how that's changed and how far we have come.
It just takes time
I would guess, it may even take till v3 to see a BIG change in design.
If they put so much time and effort into this design, they may want to run with it, mostly the same for a second year, and improve the internals, battery life, perhaps reduce the black bezel area around the actual display, which is quite large really for the size, and get the pixels out nearer the frame as there is no need for the bezel unlike an iPhone or iPad.
So perhaps a upgrade/tweak for the 1st refresh, and save the LARGE change for v3.