Also, if you have an earlier flight you can register with Guest Services for early disembark or you can do the self-carry and be one of the first off the boat (and thus to the taxi line).
Although when we got off Wonder, we were one of the last groups off and there were still dozens of taxis - they know where to be on disembark days!
Side note: the taxis in Vancouver were (in our experience) some of the cleanest, most well run and most honest, polite drivers we've experienced.