This Hong Kong Magazine Seems Pretty Confident that PS3 Slim is Coming
Confident enough to put it on the cover!
Check out the cover of the next issue of Hong Kong's weekly game magazine Game Wave:
See the picture of the PS3 below the magazine name? The text next to it says something to the effect of "Slim PS3 appears at the end of the month."
I personally don't know much of anything about the Chinese game industry, so I can't vouch for Game Wave, or the site Crossmedia, where the information about the magazine's next issue was posted. However, frequently updated gaming blog Game Jouhou, where I saw this story, says that the site is known for having reported a number of leaks.
Of course, Crossmedia wouldn't be alone with this particular leak. From overseas reports of retail listings, to local reports of lowered shipments of standard model PS3 units, PS3 slim looks like a sure fire candidate for gaming's worst kept secret.