Did they or didn't they? Only Terry Semel (Yahoo chairman and CEO) really knows, it seems. Did Microsoft attempt to acquire Yahoo, to the tune of $80 billion or any other amount? Semel said on Thursday that the "Microsoft wants to buy Yahoo" rumors are untrue. But Semel also said that Microsoft did approach Yahoo about buying a stake in Yahoo's search business. Meanwhile, speaking of Yahoo, Microsoft CEO Steve Ballmer is predicting it will take Microsoft at least five years to catch up with Yahoo and Google in the search/ad space business.