I'm also a sponsor living abroad. With our application I sent letters from family and friends saying they know we're returning and how they're willing to help/support us when we arrive (place to stay, car to use, etc.), a letter form my Canadian bank stating that I'm in good standing and outlining the accounts and products I've maintained while being outside Canada, a letter from my foreign employer stating that she's aware that I'm returning to Canada and that my employment will terminate when my husband is approved, correspondence between myself and a venue for an event we're hosting in Canada in November, and plane tickets from my visits home to show my continued connection to Canada - and of course a cover letter explaining our situation (want to start a family in Canada, plans to be abroad were always temporary, etc.). Later, without being asked, I submitted a contract/receipt from the venue I mentioned earlier and plane tickets to Canada (return flight - was cheaper and incase my husband has to go on a tourist visa) - and again a note explaining everything (why the tickets are round trip and that I don't intend to use the return unless the application is refused). We received our GCMS notes and can see that they received the things we submitted after the whole application, but apparently no one actually read it because it got categorized as proof of relationship.
IF they request more proof of our intention to return I will have my foreign employer write another letter saying I've given my notice, send another contract/receipt from another vendor for the event in October, and a facebook conversation I had with a former colleague about possibly returning to work there when I return (unfortunately the company may be closing/being sold), and I'll also do a little job searching to have something more to show.
IF they request proof of my husband's intention to return he'll do a little job searching and also, as he has an interest in studying when we get to Canada, he can also contact some colleges inquiring about courses and fees, etc. But I've just thought of these things now. Until I read about your situation, I never expected they might ask him for proof of intention to move to Canada! I thought going through this whole pain-in-the-ass process to get PR would be enough to show he wants to live in Canada!!!
Good luck! And please let us know what happens!