The Rolling Stones' plans for 2012 -- the band's 50th anniversary -- remain up in the air, but one thing definitely on the agenda of guitarist Keith Richards is a scheduled meet-up next month in a London studio with his Stones bandmates Ronnie Wood and Charlie Watts -- and singer Mick Jagger is welcome to join them.

"We're just going to play a little together, because we haven't played for three or four years," Richards tells Rolling Stone. "You don't necessarily want to rehearse or write anything -- you just want to touch bases. That's a good start: me, Charlie and Ronnie. Mick's welcome, and I'm sure he'll turn up, but right now we just want to get our chops down."

Could this eventually lead to the Stones actually booking some 50th anniversary gigs for next year? "I just hope we can perform live," Wood says of plans for the big anniversary. "It'd be great to see if that old spark is there."

Meanwhile, the Stones' recent 'Exile on Main St.' and upcoming 'Some Girls'  reissues will likely be followed by revamped versions of 'Beggars Banquet,' 'Let It Bleed' and 'Sticky Fingers' -- if  producer Don Was has his way.

"There's so much material," says Was. "If they never went in the studio again, you could have a new Stones album every year for the next 50 years, and it would all be good."