AMD has been spitting out new graphics cards like crazy since launching the Radeon HD 5000 series five months ago. With today's release that translates into almost two new graphics cards each month.
Looking at the budget and mid-range segments you'll notice that there is no more than $40 separating each card. So why the big gap between the Radeon HD 5770 and 5850? As it turns out AMD has been planning to plug this hole all along with yet another offering. The Radeon HD 5830 is expected to come in at somewhere around $250, ~15% cheaper than the 5850.