The PC industry has been shrinking for several years, and while the reasons are clear, many questions remain. Key among them are whether this shrinking is a permanent condition, or whether the PC industry plateaus at a new if lower level.
Generally speaking, I do expect the PC market to continue to contract over the long term, and Microsoft, Intel, and their PC maker partners have all issued guidance to support this opinion. So the question isn't whether it is happening, but rather at what speed it happens.