Maybe. I'd guess they're still considering what a new PHB would look like. Would a slightly updated PHB really sell well? What classes would go in it? They certainly don't want to reprint the existing one without updating it, yet doing that is a fairly significant investment, creates yet another item needing to be stocked, and might not really garner enough sales to make it a profitable book.
Beyond that what would happen with the other books? If you print a new book that replaces the existing PHB then you've also probably largely obsoleted the rest of the core books to some extent. Not only are existing stocks of PHB1 the issue, but PHB2, PHB3, all the Power books, etc.
OTOH they can continue with the newer lines of books, MVs, the newer themed types of supplements, potentially other types of books that we haven't even heard about. The older books can just slowly fade into history and game elements they didn't like that well can gather the dust of history. I'm guessing few, if any, 4e books will see a lot of reprinting. Instead their content will just linger on on DDI and new stuff will take its place.