I get my info from this forum, and a bit from personal experience (and my own lawyer). I'm sorry I can't find all the official links at the moment. (more senior members, feel free to do so, if you can)
there is no way you can get an open work permit. that info I get from my lawyer, as well. I have begged her for work-arounds, believe me. my understanding is that they are only for certain categories of people who can get open work permits, namely, (1) international students who have graduated from a Canadian university, (2) people who apply for PR inland, (3) spouses of people who are already here on temporary work permits.
there is a slight chance she could get a closed work permit, if she is highly skilled and can meet all of these requirements:
http://www.cic.gc.ca/english/work/apply-who-eligible.asp#outside. however, it could be tricky convincing an immigration official that she intends to leave at the end, if she already has a PR application in process.
and if she shows up as a visitor in hopes of finding an employer to sponsor her closed work permit, again, I am afraid the immigration official may not let her in.
personally: I came to Canada on a closed work permit (before I knew my future husband here existed), and I had to attest that I intended to leave at the end of my permit. at the time, that was the truth. things changed later, when I met my husband. but if I had lied on it (imagine I already knew my husband and was using this as a way to get in faster), I would have put my entire future PR application in jeopardy. that's what I am afraid of, for your wife.
my job ended 6 months before my permit (which expires this week), and for the entire 6 months since I have been trying, full-time, to find an employer here to "responsor" my work permit - I have a Ph.D., but still with no luck. in my experience, the LMO (labour market opinion) is not easy to get, and scares away most potential employers.
also check this out, to see if she might qualify for a job that doesn't need an LMO:
http://www.cic.gc.ca/english/work/apply-who-permit.aspif that's the case, I think she would only need a job offer letter.