Developers can now adjust their own discounts and run their own sales on Steam. Valve has handed over control of sales and discounts, and given devs the chance to sign up for opt-in weeklong promotions.
Thanks to new options available via Steamworks tools (as posted on Reddit), Valve's partners will now be able to control custom discounts (particularly useful for devs now there's a ‘Recently Updated' tab on the front page of Steam - expect to see more targeted sales as studios take advantage of the additional exposure), and sign up for automatic weeklong promotions up to two months in advance (albeit with a two week maximum).
This is yet another move by Valve to bring about a more open PC platform, with developers large and small now able to take more control of their own pricing and promotions. How this will manifest itself in the future, and what the longterm repercussions of this shift will be, remains to be seen.