Would make much more sense to invest in BBC2 Scotland and launch that in HD than launch a standalone channel. More often than not the 7-8pm slot on BBC2 seems to be repeats anyway so an easy slot to put an hour of original content in without seriously displacing network content. The 9pm news hour would have to go but not sure anyone outside the BBC wants that anyway.
Only in the BBC could you imagine a negotiation going like this:
"So we'd like a Scottish Six. One hour national and international programme from Scotland to replace the BBC News At Six and Reporting Scotland. We already do Reporting Scotland anyway. We'll leave the News at Ten because it's more international."
"Nah. Tell you what, would you like an entirely new channel including a completely separate news hour from Glasgow at 9pm instead?"
"I'm sorry, what? Er ... yes, sorry, we would."
It's an episode of W1A waiting to happen.
The BBC appears very conscious of the fact that audience appreciation of the corporation is lowest in Scotland for a variety of reasons. The aftermath of the independence referendum led to some ill-feeling, but it's also the most distant from London so there's always been an issue. The Social is likely to have been part of a bid to get younger people back on side, and I suspect the BBC Scotland channel is a bid to kill two birds with one stone - winning back an older audience and dealing with the Scottish Six question.
If it's not handled correctly though, with adequate funding and huge publicity, then it risks joining the shipwreck that was Scotland 2015 etc. It's the one part of the country that still has strong competition from STV - indeed, Scotland Tonight killed BBC Scotland's 10.30pm show, which was the previous "you can't have a Scottish Six but how about this?"