I think for me that's sort of the point of this story. They're very early in the relationship as far as I can tell and it's all been very 'steady' so far, just dinners down the pubs and suchlike. It's certainly not a relationship built on lust, until today Ailsa hadn't been to Alf's house before, so I think it'd be quite unatural for them to have such a good chemistry right now. Perhaps 'unatural' isn't the right word, it's rather - some couples have it straight away, some couples take time to grow.
It goes to show how much the show has changed when Pippa said "Fancy a game of...chess?"....and she literally meant chess.
There are some very interesting dynamics being set up at the moment between Alf/Ailsa/Roo, Roo/Frank, Bobby/Carly, Fisher/The Fletchers...I think overall the first week has been a bit of mixed bag, but not bad for a first week - it's certainly left me wanting to watch more to see how the set-ups are developed.