I just noticed this on the Acura website. They've downgraded the HP on the TL to 258, the same as the 06 330i.
Out on the Fujita webite, there are several dyno's shown, one for an 05 TL.
http://www.f5air.com/applications.html
It only dyno'ed at 205 HP and 187 ft/lb of torque. This for a car rated at 270 HP. That's a 24% decrease from the stated HP. I guess Acura lowed the HP to bring it more in line with the truth. Even if it's truly been at 258 the whole time, that's still a 20% decrease.