Are you applying for Permanent Residence as well?
We got married in May 08...applied to sponsor my wife in Sept, and then once we were approved for sponsorship we filled out a Temp Visa application. We specifically referred to our permanent application and that sponsorship was approved. We gave details of what our visit was for, Christmas, meeting family, investigating Toronto before the next step, etc. We also gave proof she would return, work at home, son at home. And they approved her to visit for Christmas.
Don't lie to get in...it will just make getting together permenently harder or impossible.
I totally agree with Frolic. Just tell them the truth and submit as much proof as possible, and then pray for luck.