Just found this on thecarconnection.com. I thought an SRT8 was pure speculation, seems it may be true!! WOW The only mistake they make is saying that the Liberty provides the platform for the Nitro, when infact the platform is all new considering its wider and longer.
2007 Dodge SUV
The first prototypes of the Dodge Nitro have just begun to hit the test circuit, but we have now learned that development of the hot SRT version is being done concurrently with the standard models. This prototype black-and-white prototype was mixed in with several other Nitro test vehicles, but its footwear set it apart as a vehicle with a much more serious pavement-biased set-up. This Nitro prototype was shod with low-profile Eagle RS-As mounted on meaty 20-inch wheels - not exactly a setup made for the trails. A deeper, more aggressive front air dam completes the look, in much the same way as on the Jeep Grand Cherokee SRT8.
The question that now remains is what lies under the hood? The Jeep Liberty provides the platform for the Nitro, and the Nitro concept vehicle shared the Liberty's 3.7-liter V-6 (the largest engine on offer). Logic would say that the Nitro SRT will be V-6-powered, giving the Grand Cherokee SRT8 a little breathing room higher up the food chain, but a Nitro SRT8 doesn't seem out of the question.