Dion has to be careful. He may think separatism is dead in Quebec, but I think we all know Conservatism in Canada didn't die after the Cons got only 2 seats in Chrétien's blowout election after Kim Campbell's government - both situations are similar, in the regard that the separatist feelings in Quebec have always been there (even 200 years ago), at least to an extent. The support to the idea simply varies : sometimes, like in 1995, it'll be around 50%, sometimes it'll be around 40%, but most of the time it's like it 'hibernates' around 15% or something (that's a pure estimation of mine here, I have to say) and is therefore irrelevant to the current issues.
Then, it's also arguable the Bloc is relevant in the first place, so...
... and I also personally believe Dion is really the most disconnected politician out there, so I wouldn't be surprised to see him claim the Libs have a chance of taking Alberta come the next elections. It would be just like him to mention that kind of unbelievably unlikely possibilities.
EDIT: Hmm... I didn't read what Dion said in English before writing this because I had read it in French. However, now that I read everything, it seems to me what he said is reported differently. Therefore, please take my post with a grain of salt.