Well goodbye 2 Deidara if he really dies... He was cool... SOOO many surprises under his sleeve...
But... He might not even be dead... There might be 2 ways he could still be alive (maybe even more) n these r it :
1) It might be a "suicide" again but in the end its just a clay clone... Or...
2) He might just do the Akatsuki-exclusive body transfer justu thing that Itachi n Kisame used...
Or his his just really dead this time