I haven't seen the report, but Mike Brunton is undoubtedly right--if they said 12 seconds, they meant 12.something, not 12 flat. I subscribe to all the Mustang magazines as well as the more generic mags (C&D, R&T, etc.), and a completely stock '03 Cobra runs high 12's to low 13's, depending on who's driving, the weather, etc. However, they can be modified very easily, and Evan Smith did run a 12 flat in one with a smaller Lightning blower pulley and the air intake removed (I can't remember whether the exhaust was modified or not). But that's with Evan driving as well. Bottom line is a stock Cobra should not be a match for a stock Viper, but there will be modified ones that could be fairly close. But of course that's always been true with all the blown 'stangs running around out there. Ford did a great job of closing the gap significantly for ~$35k, but I wouldn't lose a lot of sleep about it.
Ronnie