Nah...MACS and I just happen to both dig cars...especially new ones, and better yet, new ones with some juice.
The previous SHOs enjoyed a really loyal following. Not quite at the same level with older women and their T-Birds, nor old men and their Grand Marquis (both groups would always seem to come in thinking that IF they were to ever trade their car in, the car's trade-in value should be about double what they paid for the damned thing). Pretty damned strong loyalty, however.
They were pretty fun to drive, too. Friend of mine had one with a black metal flake paint job that was very nice. Lincoln had a similar run when they put out the Mark VIII, which was basically a beefed up and pimped T-Bird. That didn't seem to canibalize T-Bird sales, and those vehicles were far more similar. I really loved those Mark VIIIs, BTW...especially the last couple years (the years with the neon taillight setup across the back). A hoot to drive.
The guys in the Corvette development team have been simlarly protective about the Vette. They didn't want GM putting a Vette engine in anything. However, once they stuffed it into a Caddy, the thing sold like...um, waffles (I hate to say hotcakes).
I think the key is, how similar or different are the cars? When Dodge came out with the new Charger, a lot of Mopar fans howled at the thought of a 4 door Charger. Eventually, Dodge had to develop the Challenger to make up for botching the Charger (although the latest iteration of the Charger has plenty of fans, too).
The new generation Mustang was a run-away hit for Ford. Caught Chrysler and GM with their pants around their ankles, as neither imagined the success Ford would have with it, nor did they have anything in development to counter it. That's why it took so long for the newer Charger, then Challenger and then Camaro. Ford scooped up a lot of buyers before either of the others were ready to dive back into the pony car segment.
The Taurus SHO, however, will be different enough that I don't think it will eat into Mustang sales. It didn't seem to do so before, and the version of the Mustang that was out at the time was nowhere near as popular with buyers as the current version.
It's hard to know what is going to happen ultimately, as the newer CAFE regulations, the uncertainty with an economy that is still in the toilet, etc., all tend to make it tough to believe right now that the usual rules to these sort of things will follow. However, if the economy recovers enough to where things return close to normal, I'd bet the SHO does more to rekindle interest in the Taurus overall, while doing little to dent the enthusiasm for the Mustang (assuming Ford doesn't tinker too much with the Mustang, too).
BTW...Taurus SHO...four door family sedan, smooth ride, AWD, not a machine for torching tires, and will have several comfort and practical features the Mustang does not. Should be very nice for long drives.
The Mustang...will still have a stiff ride, much smaller inside, noisier inside, you can burn through a set of tires as quickly as you want, and it's more visceral than practical.
The SHO will be the car guys who have some money get when they wanted a Mustang, but couldn't have gotten one, because carrying the kids and carseat in the Mustang wouldn't have been practical. The SHO will be the car the wife is telling to "grow up and behave", which will make it fun, but the Mustang will still be a hooligan.
