Hi Ryan
I have tested this exact situation and actually the test is still running. I haven't seen a penalty, but the page doesn't rank as well as the real page did (They are 7% alike using the tool you mentioned). I'm also pretty sure that the value doesn't get transfered as if you use a 301 redirect.
I wouldn't recommend using rel canonical for non similar pages as it's neither relevant or good for the user but also because it's apparently well thought through by Google to prevent webmasters from cheating.
rel canonical should only be used if the two pages are very similar or have the exact same story.
