I'm a little disturbed by this move by the Beeb. Don't get me wrong I think both Brundle and Coulthard are incisive in their comments in relation to the car, the drivers, and the race itself but do they have the wherewithall to commentate together on a full race?
Who else could do it? I'm not sure to be honest...but two drivers could lead to an involved and convoluted discussion on a single issue leaving the viewer to get on with watching the race.
The beauty of Walker/Hunt and Walker/Brundle was that, regardless of Murray's fantastic knowledge of the sport, he would always bow to the expertise of his co-commentator on matters relating to the driving experience. J. Allen did the same as did J. Legard. J. Allen had a hard act to follow, while J. Legard was chucked into TV at the deep end.
The TV commentary will be missing that come the start of the season. Martin Brundle has said that he's done a fair bit of journalism and that has prepared him, but it's not journalism that matters, it's passion for the sport - the passion of the well informed fan who delights in hearing the revelatory inside knowledge of Messrs B. and C. as it is weaved into the overall race commentary.
The other question is, of course, can DC cut it? I think he can - it was obvious from last seasons punditry that he took his job very seriously and didn't swan in expecting to be brilliant. During the first half of the season his notebook was in plain sight and he wasn't afraid to refer to it when he needed to.
Best of luck to both of you - but this fan can't help but feel that something will have been lost...