Well it seems like it's happening.  The boys are done.  Last night they officially deleted their Twitter account:

Here's what we know.  Joe has been hanging out w/ Demi's sober coach Mike Bayer.  Kevin flew from NYC to LA to see Joe, and seeing this video, he doesn't look happen, at all! You can hear him say something like "you'll see."

Source told STAR that Joe does have a drug problem: 'He’s been dealing with substance abuse issues for quite some time. His management team, friends and family have been begging him to seek help. The tour would have never survived with how Joe was behaving.'