I have been to several forums online, and after going through the timelines of various candidates, I found that Ontario PNP is taking approximately 2 months for employer approval and 1 month for nominee approval in 2009. Last year (2008) it was different, it was taking 1 month for employer and 1 month for nominee approval.
If your employer has been previously approved then it might take less time but otherwise it is taking 2 months.
Here's what i did. I called up PNP saying that "my company has applied for employer preapproval at Opportunities Ontario PNP and we haven't received any confirmation mail about our application. Its been 2 weeks."
The lady at the other end asked me the company name and then said she can confirm that we have received your application and are processing it."
And then in a weeks time i got my file number.
One more thing, when they send the company the mail about the file number, they also mention that NOT to contact PNP regarding the status of the application as it will delay the application processing.
Which category are you applying in ? International Student ?