What would be their motivation for that?

It seems like a very different set of cultures, and it's not as if the stock-holders are revolting (no pun intended).

Personally I'd prefer some good healthy competition in mobile/tablets/HTML5 - as we saw what happened to the browser when left to one dominant player...

The browser market languished with one dominant player because that player specifically wanted to kill the market. Microsoft/Bill Gates didn't want the browser to take off. They wanted to become the dominant player so that they could just funnel everyone away from the browser and to their other products.

On the other hand, if Google were to have the only browser on the market, they have incentives to keep improving it.

Not that I'm advocating a one-player browser market with Google at the helm. I'm just stating that the goals matter. Having a single dominant player isn't necessarily the death of innovation, so long as they have incentives to keep innovating.

Never. Not in the next 10 years. They are based on extremely different philosophies and gain money in very different ways. If this would happen, it'd be the death of one of them.

Wanna bet? I'll give you 3 to 1 odds.

Might I suggest http://www.longbets.org/

Over two years I'll give 10 to 1.