When reading through this thread I notice quite some prejudice and narrow-minded reflections without even knowing the talents, credentials and potential of the newly hired AMG guy. So I'll stand up for the guy (and the decision).
///M is a brand and BMW M GmbH a company, not a person. So, true, it is shaped by the people it hires. But, as life goes, people come and go. New blood can contribute to new ideas or improve existing ones, in other words: evolution (for better of for worse).
Just imagine for a moment that a guy developing Mini Cooper cars would be dropped in the seat of the ///M Division boss and, hence, gets important decision power. Are you gonna take the piss out of him because of his past experience ("For crying out loud: a Mini Cooper guy spearheading BMW M. Were their brains out to lunch or what ?!"
) ? Actually, you know what, this already happened:
"The [1M] development time of the engine was very short – engineers took only about a year to build it if not less, beginning in October 2009. In December 2009 the decision was made to build the 1M. Dr. Segler championed the project and made all major decisions. Took around 1 year to develop and test the car. [...] Dr. Segler was emotional and had a few tears the first time he saw the car in completed form. In a broken voice, he said, «We need to build this car»."
"The time window for this car [1M] [was] extremely tight and originally enthusiasm was not apparent until Dr. Kay Segler came to the M Division. [...] There had to be a lot of arm-twisting in the BMW Board because of the tight window between generation 1 and generation 2 of the Coupe."
"Actually, the first time we came up with the concept [of the 1M] we got shot/shut down. But at that time Dr. Segler was pretty persistent as we know him. Went back in and presented the case again [to the BMW Board], and we got the approval. And that's when everything started happening very-very quickly. We never developed a car so quickly as the 1 Series M Coupé. [...] I remember the day that Dr. Segler came to me and said «Okay Brian [Brian Watts - Head of Marketing & Sales for BMW M worldwide], we got approval. What are we gonna do ?». And basically he gave me three days to come up [with] the whole marketing concept. It's challenging as it is sometimes. But it was a great project. It's been an extreme success. We're so happy with it."
(http://www.bimmerfile.com/2011/08/21...les-for-bmw-m/ - Quote: 05:29-06:24 of the BimmerFile#54 interview of August 2011 with Brian Watts (Head of Marketing & Sales for BMW M worldwide))
People may tell about Dr. Kay Segler and ///M cars what they want, but without him, the 1M would not exist in the way we know it, or would simply not exist at all. He was the 1M kingmaker.
Give the AMG guy a chance. The proof of the pudding is in the eating.