Doug, I took so long to reply because I was waiting for some response from THX, Dolby, or DTS to my e-mails. (The silence is deafening, at least so far. To give THX credit, they state they don't reply to most mail). Also I wanted to study DTS before I tried to talk about it.
Anyway, re your question about dipole/bipole DD 6.1/DTS, etc... Both DTS and Dolby go to great lengths to explain that THX is not a competing standard. At the risk of over simplifying, Dolby and DTS concern themselves with getting the sound into the system (often referred to as the "A" path), and THX is a standard for playing that sound back into the theater (often called the "B" path).
Therefore, the THX standards are compatible with both DD and DTS playback. The requirement to use dipole surround speakers only applies to a Home THX Ultra setup, by the way: THX Select allows direct radiating surrounds. And as Larry has often pointed out, you can get great sound without a "THX certified" setup, too.
BTW, anyone know what the THX Ultra2 standard consists of? Sheesh...
