If it's released by the end of year I will most probably choose to
wait. Now, if the cost is 50%, I think I'd just get another D300 or a
D80 if the price drops.
The D80 was about $900 nine months ago, and by that point it had already been on the market for some time. The current body only price is about $730; 50% on top of that is right at $1000. I think the "D90" will cost at least that much when first available, if not more.