well depending on where you live it might be better or worse that other areas. personally i think you'll get hosed, badly.
i just bought an 08 3i touring with the alloys, fogs, 5spd, etc. got an extended warranty for bump-bump to 50k miles and they did the fabric and paint treatment with a life of car warranty for 14,5k out the door, 4.9% 48 mos.
the 3i touring value is dirt cheap, and with the 3s in general they are going to be trying to blow them out asap. the 09 3 and 6 are getting a face lift and the factory that makes the 3 is being re-tooled. they will start delivering 09s (3 and 6) to dealers in nov/dec.
you might get them to roll the negitive equity into the speed 3 but they are getting MSRP for them. i know, im going to attempt to buy am 08 speed 3 tomorrow. only bargaining tool i have is that i just bought a 3i and they know im not effn around. they can have a two mazda customer bringing them all in for service for the next few years or not. i told the sales guy today that if they screw me on the speed 3 deal i wouldn't bring the other mazda in even for air in the tires.
good luck. they are great cars and if you like this body style you should go for it.