Upcoming ( not necessarily summer ) d20 books I'm eager to check out:
Fantasy Flight's Sorcery & Steam
Green Ronin's Psionics Books
Green Ronin's Unholy Warrior book
Eden's Book of War &/Or Malhavoc's Cry Havok Book - the cover alone looks worth the $
Necromancer's City of Brass
Fast Forwards ( Yes, I said FAST FORWARD ) CrossGen Setting Book
Atlas/Penumbra's Fantasy Bestairy
Scarred Lands Class Books ( If they would only reprint and retool all the PrC's they have littered accross their product line I would buy these FOR SURE just to have these all in one place. character generation is the worst part of playing in the Scarred Lands )
I won't hold my breath for:
Privateer's IK Setting Book
Affinity Game's Windaven City Book
Eden's Archipelagos
Fierydragon's Atomic City