According to Weekly Shounen Jump released on Nov 17th, the publication of D.Gray-man
will be withheld for a significant period of time due to the physical condition of the author Hoshino Katsura
Source: Scan of Weekly Shounen Jump
This is the third long break of D. Gray-man publication.
First break: 2005 Nov issue - 2006 Jan issue
Second break: 2006 Mar issue - 2006 Jul issue