Sure does! Just turn it sideways (or upside-down, if you are tired of the power button being on the bottom) and it automatically rotates.
SOME apps (usually games) have a forced orientation and will not rotate any other way, because that's the way they want the screen laid out.
Also, be aware that you can lock the rotation so that it will not rotate when you don't want it to. Touch in the upper-right to bring down the little settings menu. In the left is an icon that says locked or unlocked. That's your rotation lock.
If yours is not locked but not rotating you may have a faulty sensor - contact Amazon.