With the 2014 Jeep Grand Cherokee becoming available soon, will the 2013 models be discounted dramatically?

The left overs will go on sale. But you don't see the types of sales they used to have. More like rebates and special financing rates. The deeper cuts do not come until later on. But by then they are pretty picked over with not much to choose from. The manufacturers know better to have huge inventories of a model right before a newer model is released. They have been quietly reducing inventories more by attrition, not replacing stock.

That is usually how it works. They put the old models on sale to make room for the new models coming in but it seems excessively early to be introducing the 2014 models. That usually happens in the late summer and early fall of each year.

Way back when they introduced the Mustang for the first time, they called it the 1964 1/2 because it came out way early.