I'm instinctively queasy about this.
We've got quite enough talented Labour MPs to fill every position without co-opting our political enemies.
If more social democratic Lib Dems like Vince Cable (who started out as Labour Candidate for Glasgow Hillhead in the 1970 election and a Labour Special Adviser to John Smith at DTI) want to be Ministers they should defect back to the Labour Party.
I don't think the Lib Dems have much to offer intellectually in terms of input on constitutional issues - there's a kind of mythology that somehow they are experts on constitutional reform when in fact they have a pretty narrowly self-interested stance on PR and most of the interesting thinking on the constitution is coming from Labour people.
The weakness of Campbell as a leader actually gives us a chance to put the Lib Dems back in the box and erode their local government base. It will be very difficult to give the Lib Dems the electoral kicking they deserve for their opportunism at a local level if we are cosying up to them nationally.
I'd prefer a bit more tribalism from the new PM rather than less.