According to AILA, the USCIS has confirmed the following with the new three-year TN regulation:

• All the TN petitions received before October 16, 2008, will be granted for the requested period or one-year, whichever is less.
• All TN petitions on or after October 16, 2008, will be granted for the period requested, or three years, whichever is less.
• The Canadian Border Patrol has also confirmed that the filing fee for TN border applications, even those requesting a three year period of TN visa status, will remain at $56.

*Please be advised: USCIS cannot grant up to three years if the anticipated length of stay, as stated in the application, is less then that period. Please be sure to review all your filings to ensure that all documents are requesting the three year period.

From AILA InfoNet Doc. No. 08102261 (posted Oct. 22, 2008)