Not in the immediate future.
The GS is the first one to go AWD, it will debut in the 2006 model.
I read recently that Lexus/Toyota is headed toward making a version of each model in an AWD platform. Given the current trend away from huge gas guzzliing SUV's, I'm not surprised. This will give them the traction option that people desire but maintain a non-truck like ride.
Coarse, like life, this could change next week.
I like in just south of Boston and can relate to the weather issues. However, a RWD car with a dedicated set of snow tires (the technology here has come a long way) from Dec to March and traction control will get you through the worst of days.
Don't give up hope. An IS is most definately doable in NE.
steviej