Blu Ray is M2TS which imports directly to the time line unless it's a commercial one with multiple audio tracks... subtitle tracks... etc. In this case you will have to demux (with TSmuxeR.... free download), remove the extra stuff and then remux with one video track and one audio track.
A M2TS will also not import with a DTS or DTSHD audio track. You will have to convert any DTS to Dolby Digital with EAC3to (another free download)
To piggy back on this subject, I kind of gave up on HD editing while working with Vegas 8. I recently upgraded to V9 and since blu ray writers and media dropped in prices, my interest has rekindled. Do I still need to convert m2t files to intermediate files before editing in V9? If so, what's the best method? I read the V9 manual and I am a little confused because some threads here seems to indicate that V9 can handle the mt2 files.