Some are, some aren't. How badly is out of true?

Generally speaking for prebuilt new wheels, even if they're out of true, I'll let them be for the first several hundred miles. Then true them. After that, they seem to be 'set' for a long time. Truing straight out of the box can be redundant and sometimes creates more strain than necessary, since you may find they probably go out of true anyways once you start riding them.