125 years after Louis Riel hanging, it seems that English assimilation is rampant among Metis. Anyaways, that's what suggest some data released by Statistics Canada in the latest issue of "Canadian Social Trends"
An exploration of cultural activities of Métis in Canada: http://www.statcan.gc.ca/pub/11-008-x/2010001/article/11142-eng.htm
According to this study only one Metis out of ten can speak "an aboriginal language" (mostly Cree and Ojibway). French, Riel's language, is also only spoken by one out of ten Metis and Michif, the Metis French-Cree Creole, has under 3600 living speakers.