How could it have been otherwise? Mandelson, twice jettisoned by Tony Blair, his closest political friend, was brought back into the fold by a man assumed to be his sworn enemy. Whether this was inspired recruitment which put country before personal opinion or the last act of a leader desperate to hold on to power, only time will tell.

But we should not allow Mandelson's appointment as Business Secretary to obscure other significant changes in the reshuffle – many of them positive ones. Most significantly for Scotland, Brown finally agreed with many observers that it made no sense to combine the role of Defence Secretary with that of Scottish Secretary. But rather than killing off the Scottish role and creating a new portfolio combined with Northern Ireland, Wales and possibly the English regions, as had been predicted, Brown restored the job to single status within the Cabinet.

The Prime Minister's Londoncentric critics were too busy working themselves into a froth about Mandelson to lob criticism at another of their Aunt Sallys – the alleged "special" treatment given to devolved Scotland. They will rejoin the attack soon enough, but we in Scotland should be glad that when Jim Murphy sits at the next Cabinet meeting he will have only matters north of the border in mind. His predecessor, Des Browne, famously said he took care of Scotland in his spare time, which said little about the importance he – or, indeed, the Prime Minister who appointed him – gave the role compared with his defence brief.

Combining the Scottish role with another portfolio may have seemed a neat trick after devolution, and undoubtedly the majority of the duties that once went with the job now lie in Edinburgh. But Scotland needs a new kind of Scottish Secretary. Instead of administrating Scotland, as his predecessors once did on behalf of London, Murphy should be Scotland's man in the Cabinet. He must press the case for Scottish interests at all times; in the current economic crisis, for example, he should immediately take up the cudgels on behalf of our vital financial sector.

In doing so, Murphy must tread with care. He is a renowned political battler, and if Brown has brought him in with an order to take the fight to Alex Salmond's SNP Government then he will be playing into the hands of those who see division as a means towards independence. Standing up for Scotland without standing on the toes of the Scottish Government is a big job indeed – and a full-time one.

Another overlooked part of Brown's reshuffle was the creation of a new Energy and Climate Change department. With the cerebral and talented Ed Miliband at its head, this gives renewed importance to two increasingly vexing parts of our lives, with fuel bills rising and talk of future power shortages, to say nothing of the risk from global warming. At a deeper level, Brown's Cabinet changes were cleverly designed to strengthen his own position by appeasing various wings of his party. Blairites such as John Hutton, tipped for a governmental exit, were instead promoted to balance the introduction of loyalists such as Ed Miliband, and Nick Brown as Chief Whip.

The return of Mandelson was of course a key – and the most controversial – part of that balancing act. We know the move was strongly opposed by at least one Cabinet member, believed to be the Brown lieutenant and Schools Secretary Ed Balls. Many around the Cabinet table will view the new Business Secretary with equal measures of suspicion and loathing.

That Brown, foiled by Mandelson after the death of John Smith as Labour leader, could countenance his return defies the convention that the Prime Minister is a grudge-holding control freak who prefers the company of cronies. And if Mandelson, owner of one of the sharpest political minds of his generation, can avoid for 18 months the kind of mishaps that plagued him in the past his appointment may prove to be inspired rather than desperate.