would it be possible to have MORE than 10 rear gears? like 11 or 12?

Yes, sure. I can't see much point to it however.

A while back I found that Shimano actually already has a patent for a 14 speed setup. This was a patent they obtained well before this latest batch of 10 speed stuff.

Of course it's crazy overkill, but if the market demands it...

I suppose that they could design more cogs in the rear but I think it would be a waste, I don't even use all of the ten right now.

What demand? What are the odds this farce would never have been foisted on us if Shimano hadn't been shocked into playing catch-up to Campagnolo, which means that they'll be pulling the plug in the not-too-distant future on 9-sp, as they did with 8-sp, etc, etc. What "benefit" is there (to anyone besides Big S)--closer ratios? If we had the option of customizing cassettes (a la Campy) riders could set up exactly what they need and tell Shimano to sod off. It'd be funny watching all the lemmings scrambling to get this junk if it didn't affect the rest of us who don't want/"need" it.

Ok, I guess I should have said: "If Shimano thinks it will sell..."

...

"they they'll be right"

Is 11+ speeds possible? Yes. Nobody seems to want it. I hope they don't force it on us. It would seem that electronic shifting is the next big thing to be offered. www.campyonly.com. Go to "rumors".

I'm sticking with 9 speed cogs for now, I build wheels and hate dish.
I'm already needing off center rear rims.

Diminishing returns set in a long time ago, when 8 went to 9. We now know
that 10 can be done with some success, but fat cassettes are just no fun.
What about mass?