The driver market is irrelevant in the ambitions of Mercedes Benz and McLaren. Both have longer term growth strategies at a corporate level that need to be exercised.

Mercedes always wanted to have a Silver Arrows in F1, bu that project was shelved in 1993 as too risky. Mercedes then entered F1 as Sauber Mercedes, with the original Silver Arrow painted black.

Ron Dennis has never wanted to sell McLaren MP4 to anyone and the partnership with Mercedes was mutually beneficial at the time.

Now the world has changed. McLaren is in a position to own and develop its own engine (buying one would clearly save cash) to bolster its road car brand. This creates share holder value and establishes McLaren as a sports car producer in its own right.

Ross Brawn had never intended to keep Brawn GP anyways. He took the opportunity to raise the share price of ex BAR, ex Honda assets with a view to selling it too a manufacturer in future. This strategy would make sense if you now own the assets and liabilities. Buy it low, sell it high = Profit.
Then engineer a role as team principal and draw a salary and share options to incentivise yourself. Bernie did, Richard Branson does it so why wouldn’t Ross Brawn?

This is very exciting for F1 if it comes to fruition. Perhaps this move will temp VAG into F1 either under the VW or Audi (or perhaps Lambo or Bentley which would make sense in the market those brands compete).

Manufacturers can be the death of F1 but if the environment (costs, rules, politics) is correct then manufacturers can be the life blood of F1.

This move by McLaren and Mercedes is not about drivers, its about corporate strategy. F1 is a business and is used to create brand equity. There is no higher brand equity than a Mercedes Benz F1 race car painted Silver and called a Mercedes benz, not a McLaren Mercedes.
Same holds true for McLaren. The customer of the MP4/12c will more easily identify with a Vodaphone McLaren than a Vodaphone Mc Merc.

Bmw is a privately owned company, they would want to sell the engine programme as a going concern to get cash back in the bank for R$D.

There is a lot of sense to all of these moves.

Could it happen?

I have been to the McLaren Technology Centre and from what I have seen they are more than capable of building their own engine.

The engine freeze will probably be scrapped soon.

do you think that Mercedes were completely satisfied with their cooperation and results with McLaren?

You mention the tension coming from scandals. But a moment’s reflection reveals that for such a high profile collaboration, the results were rather poor…

3 drivers championships, and 2 constructors??

Toro Rosso won the Italian GP last year with a Ferarri engine, and Red Bull have won 3 races this year with a Renault engine. Although not even Toyota themselves have won a race with their engine…