Just to put my own two cents into the completely speculative and asinine debate about Motion+'s implementation in Zelda Wii, I will say that there's plenty of ways to implement swinging (and calibration) such that you won't get tired and you won't actually notice that you're calibrating, especially if sword bouts are kept short and isolated.
The calibration motion could be what triggers Link to pull out his sword, for instance, or it could be the trigger for some sort of special attack, or it could be the motion for using your shield or any number of other actions. It could be that you won't need to do it that often or only at the beginning of a fight. It could, admittedly, be an annoyance that happens all the time, but until we see gameplay, we have no earthly way of knowing how well it'll work.
Combat has always been a relatively small part of what makes the Zelda series unique and indeed, a relatively small part of the the games compared to other big series. Yell that the sky is falling because of waggle all you want, it'll only ruin your experience if you fixate on it.