While this is true, I have been enlightened about a different way to approach this for music-oriented systems. Because my system is used over 90% of the time for 2.1 music, I was looking for a quality 2 channel power amp to augment my receiver for the mains. At peak levels my receiver would go into protection mode so I wanted to double the power there. It's been fine for HT surround sound.
A dealer suggested consideration of an integrated amp. My knee-jerk reaction was just that, another DAC I don't need, more complexity and cost, and possible degradation of sound quality. What he explained was that I would move all the music oriented components to that integrated amp, including Bluesound Vault, turntable and CD changer. The amps suggested have an "HT Bypass" circuit to connect to the receiver for when watching BluRay disks, internet video or cable TV and wanting surround sound. I don't yet understand the fine details of how that circuit works, but the proposal in theory makes sense. The multi-channel receiver would rarely be on at all.
Some of the units suggested were Hegel H160 or H300, Parasound Halo Integrated, or the new NAD M32.
None of this should matter to the OP. Assuming he has a 2-channel power amp already, the way he'd do it is just pre-outs to the amp for the main L-R channels and be done with it.
Yes, as others have said the HT setup would be to put everything through the receiver and with the ARC (audio return channel) to the TV the sound comes through the TV when the receiver is off. I don't know if an older plasma TV has the ARC, though it usually works fine even without that.