I've listed the biggest game for each month during the summer (June, July, August) to be released for each platform....a good indication of how each system will perform during the summer:

Wii
June - Resident Evil 4: Wii Edition
July -  Final Fantasy Crystal Chronicles: Crystal Bearers
August - Super Mario Galaxy

DS
June - Sim City DS
July - Pokemon Diamond/Pearl
August - Legend of Zelda: The Phantom Hourglass

PSP
June - Tomb Raider Anniversary
July - Manhunt 2
August - Monster Hunter Freedom 2

PS3
June - Ninja Gaiden Sigma
July - Singstar
August - Stuntman: Ignition

360
June - Forza Motorsport 2
July - Alone in the Dark
August - Bioshock

sounds interesting. i hope you're right that we can play FF CC in europe in July ! Galaxy in August makes me happy too. personally, iam also looking forward to Scarface in June (Wii)

Yeah it's gonna be a good summer for the Wii....not so lucky for the PS3 though....there was much on the list to choose between.  That goes for the 360 as well.

Two Pokemon to rule them all, and in the Nintendoness bind them!

Alone in the Dark is Q4 2007, so forget July for that one ;) Plus you're forgetting Colin Mcrae: DiRT for the 360 and PC in June + Shadowrun, Flatout and Two Worlds.

Sorry about AITD...it was on one of the sites for July...anyway, I've selected what I think will be the biggest game for each month...and Forza is the biggest game for June IMHO.

True, but Two Worlds will be out in July for Xbox 360 so that is probably the biggest 360 release for July

Where did those release dates come from?

I think you are missing the first wii online game for the UK, Mario Strikers football. PAL release date is May 25th. Granted May is not on your list, but being that it is at the end of May and it is football and it is online it may be Wii's best selling game for June. Much more so than the re-release of RE4.

What about Lair ? or GRAW 2 (for PS3)