I am in a similar position like the original poster, but little bit complicated.
I got married after I received my COPR, but before landing. I notified CIC by emails, but did not get any reply. So, I tried my landing In Nov' 2012 (as my visa was expiring). I do not live in Canada now. My landing this time could not be finalized.
Thereafter, I have e-mailed CIC many times on adding wife to application, but still waiting for their reply.
Now I am keeping documents ready to add my wife. Is it necessary to send IMM0008DEPENU form? On the checklist it says, IMM0008DEPENU is required when the number dependent is more than 5.