The ATI Radeon HD 4830 graphics cards are now available. It seems AMD decided to do a quiet launch but The Tech Report noticed NewEgg is selling cards from HIS, PowerColor and Sapphire for $130:
Newegg already has HIS, PowerColor, and Sapphire variants of the 4830 in stock, and it's selling them for $129.99 before shipping. Each model features 640 stream processors, a 575MHz core clock speed, 512MB of 900MHz GDDR3 RAM (that's an "effective" 1800MHz), and a 256-bit memory interface. By contrast, the vanilla Radeon HD 4850 has 800 SPs, a 625MHz core speed, and a 993MHz memory speed. Those perks will cost you at least $30 more before any rebates, though.