I am working in the US on a TN-1 Visa under the NAFTA Treaty. Can I obtain from my employer a 1099 or other verification of income requested by Revenue Canada?

TN (Trade NAFTA) status is a special United States immigration status unique to citizens of Canada and Mexico.
Your employer must send you 1099-misc by Jan 31, 2009. You must pay taxes in the U.S.

I suspect that you will most likely get a W-2 vice a Form 1099-MISC. Regardless, that will be the verification of income needed for the Canadian government, and the 31 Jan 09 deadline still applies for the W-2.