Today at 12 noon ET, the Sony press event will be happening at Gamescom in Cologne, Germany. At the same time, the Sony Playstation Network will be down for maintenance. There've been lots of rumors that the PS3 Slim, along with a price cut, will be announced at Gamescom but that shouldn't involve the Playstation Network or Playstation Store (they don't sell hardware via the store). So what gives? Sony must have something more up their sleeves. We'll know in just a few hours.
One thing we do know now is that a price cut is real. Or at least, a temporary price cut is real. Engadget shares images of ads from both Kmart and Fyes reporting new $299 and $399 prices for the 80 GB and 160 GB model PS3s, respectively. You can see the ad on the Kmart homepage now (click on "PS3 Price Reduction" on the right side of the page), though the actual PS3 page at the site still has old prices. The Fyes ad has a "While Supplies Last" disclaimer, which suggests they're clearing out old inventory to make way for the PS3 Slim.
[UPDATE: Some online retailers have already jumped the gun and are listing the PS3 Slim for $299, saying it'll be available on August 24th.]