Apple had a major event last week, and it unveiled new versions of its iPad. Normally the world goes crazy when Apple debuts a device, but the reaction to these iPads was decidedly muted. They were thinner and had more horsepower, sharper screens, better cameras, and Touch ID. But they didn't generate anywhere near the excitement of the iPhone 6 last month, or of previous generations of iPad. All that points to an increasingly clear trend: tablet computers may be here to stay, but they are not going to replace the laptop or PC the way many people once thought they would — at least, not without a drastic shift in philosophy and marketing.