I think thats really him. Probably made himself into a puppet so he can live forever. Something like Oro.

I got the feeling Deidara's going to die rather than Sasori. Kinda like Sasori, pretty cool enemy. Maybe Gai Team would defeat their nemesis and in the nick of time save Sakura (But Chiyo would die).

Naruto and Kakashi's too far away to be helped.. Hence imo Naruto's going to hump Deidara's corpse.