USCIS' processing for I-129 petitions requesting TN visa status keeps fluctuating. For quite some time, USCIS had been achieving its goal of processing these petitions in 2 months. However, recent processing times have been fluctuating between 2 and 5 months.
According to the most recent processing time information for the Vermont Service Center, USCIS is now processing I-129 TN petitions that were filed on May 29, 2011. This means that USCIS is now adjudicating I-129 TN petitions in about 5 1/2 months time.