Nope. People thought that when iPads came out and that couldn't have been more wrong. Tablet/PC integration is the future, but traditional computers are safe.
A bit, I was just thinking about this today. My laptop charger broke and I'm waiting on my replacement to ship so I've been using my phone for everything the past few days. My laptop seems kinda clunky in comparison now.
They'll probably never be completely obsolete but they've already definitely fallen by the wayside a bit. Smartphones + tablets cover a substantial chunk of what people traditionally used computers for, and they're less cumbersome to use at a moment's notice.
