macaroni:I just think it would de-mysitfy the name if used on a "mainstream" model.
Well, bear in mind that they'll want the new car to beat the benchmark that'll be set by the Murcielago SV. That car is expected to have around 700hp and weigh just north of 1500kg. If they pack that kind of power into an all-new, lightweight platform, we could very well see an absolute monster car - the first Lamborghini to compete at the ultra-high-end since the Countach, and the first F40/F50/Enzo competitor we've seen from the company. That would not be a mainstream car, and would not come at a mainstream price. It would make sense, too, because the Gallardo and Murcielago have always been far too close - the flagship needs to be taken waaaay upmarket.
For those who don't know much about Lamborghini history - the Jota name is pretty much the ultimate designation for a Lamborghini, and goes back nearly 40 years as others have explained. The very most valuable Lambos out there bear it - the Miura SVJ, which are factory replicas of Bob Wallace's original Jota (which was a 440hp, 800kg monster that was used as a testbed for improving the Miura platform, spawning the SV the following year). These cars are worth several million pounds.