Except that he no longer dyes his hair dark, I don't see much of a dif, he's been toppling like that on stage since the nineties and probably even earlier. Same about his sparse and sometimes random playing, it's part of the Stones charm not to overcrowd everything with guitars - spare me the onslaught of the E-Street Band of three guitars strumming all the time. The Stones have so much instrumentation on stage, you have to restrict yourself. I also notice that compared to the seventies and eighties, their Jumping Jack Flash has been de-hard-rocked again and sounds more sixties than in a long time. That is not a bad thing.
On the last tour there were respectable rumors that there were two guitarists behind the stage to cover for both Ronnie and Keith who were ailing from their respective demons. That might be so, but in truth I believe that both of them have been doing it for so long they can tour another 20 years before they become unable to play their parts. It's not the Mahavishnu Orchestra you know.