I'd think using a low-interest credit card promotion as a short-term loan would be the way to go if you can't pay cash. Even if you have the cash, if they offer a 2.99% rate, keep your cash in a higher-yield money market account and come out ahead.
The big turd in the financing punchbowl is insurance. I'm pretty sure financing a bike through a bank or dealership requires you have full coverage. If you ever need some excitement in your day, call around for quotes on a new GSXR 1000, R1 or the like. Talk about high risk...I've heard of people paying about 1/3 the value of those $10,000 bikes in 1 year of insurance premiums.