Do not forget that Norilsk is very agressive and bought Lionore (including their Activox technology for refining metals) last year.

The top three candidates to launch a buyout, in my books (and possibly top two if Vale buys Xstrata,) are Vale, Xstrata, and Norilsk.

Though frankly, I would not be keen to see a top Canadian mining camp (if it turns out as expected) go to a company from a country that makes no bones about using resources for political means.