I am currently working in Canada but my work permit expired on June 30, 2014. I applied to extend my work permit on June 22, 2014, and I was informed that I could keep working until my work permit extension was processed. I was recently offered another job which is much better than my current one, and I wonder if I can switch employers while I am waiting.
Although you have implied status and can continue working for your current employer, you may not be able to switch employers, depending on the type of work permit you had. If your work permit was open (for example you were on a student work permit and you are waiting for your post-graduate work permit), then you could switch. However, if your work permit was restricted to a particular employer, then you would likely need to apply for a new work permit (and perhaps a labour market opinion (LMO)). You will need to get specific advice for your particular situation.