well here is the link so you can read it your self:
Bungie.net : Inside Bungie : News

but if you don't, these are the matchmaking changes for august:

Matchmaking changes for August, 2008:
Ranked
Team Objective

• ADDED Oddball
• ADDED King of the Hill
• REMOVED Ghost Town from symmetrical map variants

Team Doubles

• ADDED Oddball
• ADDED King of the Hill
• ADDED 2 Flag on the Pit
• ADDED 1 Flag on Blackout

Ranked Big Team Battle

• “Heavy” map variants added to Slayer rotation
• Standoff Heavy modified for more insanity
• ADDED Sandtrap Heavy

DLC
DLC Slayer

• Increased weighting on Cold Storage

Hardcore
MLG

• REMOVED MLG Blackout

Double EXP Weekends (In order of appearance)

• Legendary Brawl (Ranked)
• Grifball
• Team Snipers
• Living Dead

IMO double team wont be as fun, but btb is getting better