The financing has been a "rolling" event for one reason or another since I bought my tractor in Jan '06. It was 0% for 48 months at the time, but they sweetened the deal to 60 months in the past year. There may be a day or two that there are not any financing deals for one reason or another, but the chances are on your side (by, like, 99.5%) that they'll still be there in the spring whenever you're ready to purchase.
Funny thing was that I paid 2/3 cash at the time and for one reason or another, I didn't even use the 0%...there was something that made one of their other plans more fitting for me. Don't recall why...something with the rebate or something. Paid it off before the year was out.