Apple CEO Tim Cook is expected to unveil a new iPhone lineup onWednesday, and it's virtually guaranteed to be a success. But that may not be his most important announcement. Much bigger news for Apple's business this week could be the long-rumored giant iPad. IPad sales have fallen for six straight quarters (and in seven of the past nine quarters). The general downward trend for the iPad -- and tablets in general -- has occurred largely as smartphone screen sizes continue to get bigger. Publicly, at least, Apple doesn't appear too worried about the iPad. Cook has noted that the number of people who say they want to buy an iPad and still haven't purchased one is large. And the big iPhone 6 Plus is selling well. So while the iPad is slumping, that's at least partially because of Apple's own gadget. CNN Money