Elton John and Billy Joel pass messages to each other through Jann Wenner.

http://www.rollingstone.com/music/news/billy-joel-responds-to-elton-johns-tough-love-in-the-new-rolling-stone-20110202

Some background: Billy Joel (and his music) used to be routinely hammered by ROLLING STONE until 1982--when, from the release of THE NYLON CURTAIN onwards, he was treated with more reverence.  For awhile in recent years, it seemed like no issue of RS would go by without some kind of reference to Joel's comings-and-goings.

With regards to Elton John's comment about Billy Joel's creative stasis: I myself wonder why Joel doesn't at least try to write new songs for, say, a Broadway-intended musical.

It's a lot better than drinking, wrecking cars and self-sorrow.