Ivy Bridge pricing is slated to fall directly on top of Sandy Bridge for comparable processors (ie i5-2500K = i5-3570K). Chances are that Intel has dropped back on Sandy Bridge shipments to clear out inventory in preparation for Ivy Bridge. While Sandy Bridge prices may decline slightly, I would speculate that it won't be much. Waiting is your best option for either outcome here, its a win-win situation. If SB prices drop and you're ok with buying that, you win....if SB doesnt get cheaper, you can buy an IB CPU, you win. Its only a month or less.
Here is a review of the i5-3570K.
Anandtech, has a i7-3770K review
Main: i5-3570K, ASRock Z77 Pro4-M, Asus GTX660 TOP, 120 GB Vertex 3 Max IOPS, 2 TB Samsung EcoGreen F4, 8GB 1600MHz G.Skill @1.25V, Silverstone PS07B
HTPC: A8-5600K, MSI FM2-A75IA-E53, 4TB Seagate SSHD, 8GB 1866MHz G.Skill, Hand-Built Wood Case