I think the reason I'd prefer to see them being friends, rather than in a relationship, just yet, is, because of the fact that Anne / Deirdre is actually dead, so prematurely. I know that probably doesn't make sense. 
I think it would be nice to see them having a friendship, and there would be potential for comedy, in it. Audrey possibly having a bit of fun at Ken's expense when he is at his most pompous.
They both are probably a bit lonely. Ken really has nobody to turn to, in his own house, and Audrey will miss Maria, who, of late, was the one she went to the pub with most.
I'm taking this too seriously
. Mostly just looking forward to changes of scene from the Platt house, and the grimness above and beneath the floor!
Something that amuses me, when it happens is, the way they randomly have Rita, walking the street, dispensing pieces of wisdom here and there, then we don't see her again for ages.