Apparently, the market is not so thrilled about the terms of the Microsoft-Yahoo (NSDQ: YHOO) deal announced this morning. Yahoo’s stock is down more than 10 percent as of 11:30 a.m. ET, erasing all of its gains since reports that a deal was imminent first surfaced on July 16 (Click on Google (NSDQ: GOOG) Finance chart to the left). It finished the day down 12 percent. Microsoft’s stock, meanwhile, finished the day up just over one percent. Possibly driving the drop in Yahoo’s stock price: There’s no upfront payment—which was incorporated into many analysts’ models about how a deal would impact Yahoo’s share price. Yahoo is saying however that its operating income will increase by about $500 million. But that will only happen two years following regulatory approval, according to the companies. And Yahoo and Microsoft (NSDQ: MSFT) expect to get the green light—at the very earliest—next year