I think he's far from finished but his decline has started. Hardly surprising given his age, his ongoing problem with his ankle and the fact he's been kicked to death for the best part of a decade. He hasn't affected games this season when we've needed him to and it's really shown up how reliant we've been on him to do that week in week out for the past few years. Still a great player, but that assist statistic clearly doesn't paint an accurate pictute as he's been way off his consistent best this season.
For me, he's past his peak, but given it was quite a massive peak there's still plenty to offer (even if it's not quite as good as it used to be).