As is the case in Football when a high profile club fails to achieve anything significant in the owners eyes in the short term (think Chelsea here), the same applies to manufacturers in F1.
Ross Brawn took a huge gamble in signing Schumacher hoping to re-create the same spark that lifted Ferrari but that was always unlikely to happen. Between Rosberg and Schumacher there have been just 1 win and 5 podiums in 3 years. That's not good enough for the Mercedes board and I'm not surprised.
What this situation has now done is to put Ross Brawn on notice that he will almost certainly be moving upwards (that "director of football" role that usually means you get a desk at the office but aren't allowed to make any of the big decisions) or outwards.
This, along with the fact that Lowe won't get an early look at the plans for 2014, remembering that most teams will start the bulk of the design work on these cars by the middle of the year, and the huge upheaval in engine regs and it would seem that Mercedes will be behind the curve at best going into 2014.
No doubt there will be a few calls between Mercedes and Lowe along the lines of "you know that company car you wanted, we'll we can't seem to get the suspension working, nudge nudge wink wink, any thoughts?"
On the plus side, for Hamilton, it will be good to have a guy who he knows and has worked with, on the job. That can only be a good thing for a driver.
I just hope there's no truth in the rumors that Martin Whitmarsh has been seen in a Lufthansa ticket office with a copy of Percy Throwers Joy of Gardening tucked under his arm.