Freezing beer and draining the beer off the ice is common practice. We also used to do this to hard cider when I was a kid, we called it apple jack.
I wouldn't really recommend freezing wort though. If you want to do a partigyle and ferment some later, or just create more wort than you need immediately, I would use the no chill method pioneered by the Aussies. Essentially, just dump the hot wort straight into a clean HDPE container, squeeze out any air and seal. The hot wort will sanitize the container and as it cools it will remain very clean as long as the cap is air tight. Basic Brewing has done some experiments too and not noticed any loss of flavor in the resulting beer.