Otherwise, Canon can take them away without worrying about the competition stealing sales.
True. And for that we all have to thank Nikon with the lowly D90...for opening Pandora's Box. Canon ramped up their deploy of the 5d Mark II when the D90 launched. (They already had plans...but they seemed to actually listen when their community asked for Manual settings in video)
I will also say that I don't think there is "any going back". A hobbiest film maker only need to experience ONE TIME...the joy of buying a 35.00 lens on Ebay from the 1950's that TOTALLY ROCKS....and it's over....they can NEVER go back to fixed lens hell. I know that I can't. Can you?