HN user
a) HP's probably offering it for pennies. Too good of a deal for any tablet/mobile player.
b) Amazon Silk is a game changer that probably has Google fuming. Buying Palm is probably a hedge bet in case Google clamps down. The end-user platform(devise, OS, browser) war between Google, Apple, and MS is to control the user data. Amazon wants to make sure it has an unrestricted piece of that data.
Product managers, not necessarily. Product owners, absolutely.
A small, product minded team can definitely handle many of the activities associated with product management. So can the CEOs of early stage startups. Dropbox, facebook, and twitter all had founders focused on the vision, avoiding frankensteinism, customer development etc.
But this all changes as a company matures and as the product becomes increasingly more complex and multi-faceted. Larger development teams (~15-20+) often start working on specific product features. The company may have numerous external partners, customers, and users that influence the direction of the product. The CEO's time may shift from promoting/enforcing product vision to more 'CEO' type activities (e.g fundraising, PR work, analyst briefing). A product manager can be empowered to align the company's resources with the product vision.