While the price reductions and new items don't appear to be live yet, log in anytime this weekend and enjoy the savings and new swag, according to a YoVille blog post by Platinum Ninja. Just enter your room in YoVille, click the chair icon titled "Edit Room" and then click "Go Shop."
After that, click any given store and look for the "New Items" tabs. This is where the new items should be when they appear. If this sale is anything like the lot of them in Zynga's other social games, expect discounts on YoCoins and YoCash.
From what's visible in the blog post's promotional banner, expect some new cars and, ambiguously enough, collectibles. Can someone say, "grilling gear?" Stay tuned to the YoVille fan page for when these deals go live for a limited time.