The reason this seemed worth mentioning is that we almost never hear of deals like this on desirable cars like the Mustang, particularly the higher-end GT models and up. From what we see on the website, it applies to the 2007 Mustang V6, Mustang GT, Shelby GT, and Shelby GT500. Lately, the only promos we've been seeing on TV, etc. focus on deals related to the V6es with the Pony Package, etc. The 0% deal that's been available since June 28 was completely off our radar screens until now.
If you're in the market and can swing a 3-year deal, this might be worth looking into, particularly if you're shopping for a V8 Mustang. Don't expect any favors from dealers when it comes to Shelby pricing, though.