I loved no opening act in Anaheim. I hope the Stones have started a precedent. I've pissed away too many hours sitting through opening acts I didn't like.
Pete Townshend said when the Who once were the "warm-up" act for the Stones, he looked at the crowd and realized they didn't need any warming up.
That was definitely true in Anaheim. The crowd was pumped from the start. Maybe even more so because there was no opening act.
(I've never understood why openers became so standard. Do they make you sit through Land of the Lost before they let you watch the latest James Bond film?)
Depending on what city they are playing, maybe have the local Rolling Stones tribute band open with the first nine tracks from Metamorphosis--it might confuse the kiddies, and it would be interesting to interview the youngin's after the show to see whether they liked the openers better than the headliners.