I don't have any Blu-Ray playback software and I can watch Blu-Rays just fine. How? I rip to MKV.
Don't worry about TMT or PDVD, they all stink anyway. Just rip to MKV and you are good to go. You will need to get ANYDVD, but that is a virtual requirement for any HTPC anyway.
As others have said, the software the comes with the retail version of your drive is crippleware anyway so you don't really gain anything by getting the retail version, unless you are OK with stereo only sound. However, I bet if you were, you wouldn't be here in the first place.