The gorillaz was a side project. It has all the members from deltron 3030 and a few new ones.
The Gorillaz:
Damon Albern/2d (better known from blur),
Kid Koala (same guy who is turntabelist for deltron 3030), and Del the funky homosapien (deltron 3030, hieroglyphics), and it was produced by Dan the automator (same guy who produced deltron 3030 and is involved with the hieroglphics crew)
Gorillaz also has Ibraham Ferrer appearing on the track 'latin samone', and Miho Hatori (Noodle/ in Cibo matto) doing bass/guitar/ vocals
Basically: Hieroglyphics, Souls of Mischief, Deltron 3030, and the gorillaz are all the same group of people collaborating and doing different side projects.