If you buy last years model you can get a better deal, but the newest coolest machine and I doubt they'll budge.
I worked at one of the larger motorcycle dealerships in Texas for a couple of years but worked back in the parts department. They sold Kawasaki, Suzuki, Yamaha, Polaris, and Honda. You can wheel and deal with them some, and they will have more wiggle room than you might think. The key is finding a good salesman that wants to work with you, just like at a car dealership.
If the dealership has any last years models on the floor and the new models are starting to roll out, they will be willing to really give you a deal on last years model. Don't expect to get 10k off the price, but it will be a pretty good chunk of change. The last dirt bike I purchased was in June 2011 when the 2012 models were just coming out. Sure, the 2012 was a sweet bike and was a completely different machine, but they sold me a 2011 for 4,000 less than a 2012.