First, Gokivo [iTunes link] just announced a new pricing option that allows you to download Gokivo for just $0.99 for the first 30 days, and then pay $4.99 per month/$39.99 a year for service from then on out. We reviewed the app in November. It was middle of the road (pardon the pun) in performance and features, but it does have live traffic and text to speech for announcing turns, so it might be worth a look at this lower price.
Meanwhile, Navigon [iTunes link] has launched a version for Mexico at $49.99. The Mexico version includes many of Navigon's premium navigation capabilities such as Google Local Search, Enhanced Pedestrian Mode, Speed Assistant, Route Planning and even a localized point-of-interest database. If you're doing some driving south of the border, or happen to live down there, it should be on your list of travel options.
I expect the new year will bring a slew of enhancements and new products for the iPhone and iPod touch -- who knows, maybe we'll even get to see a tablet navigator before 2010 is through.