No problem,
i searched for that thread, by the way:
"Reported Problem: TB specs advertise 8GB internal storage but available storage is 2.41GB.
No Solution: Tracking discussion here. <---- NEW 3/22"
so, you're not missing anything from that thread.
however, further research yielded this thread:
Where is the other 5gb space balance from 8gb internal? [Archive] - xda-developers
few answers---not necessarily all reputable people or verified correctly, but from speculation:
*The main culprit is the VZW Navigator. The map for all of NA is stored there and that is a few gigs by it self. The second culprit is the Let's Golf app from Game Loft. Rock Band is not preinstalled on the phone that's downloaded as an .all on first run.
*Htc rep I spoke with at launch stated some space is bloat but there's more space for future proofing the phone. Androids OS keeps growing and htc wants the bolt to be able to update past gingerbread to ice cream and so on.
ALSO:
http://www.droidforums.net/forum/htc-thunderbolt/133245-internal-memory-3.html
"According to the HTC forums, they partitioned the card. From Almost 70% of Internal Memory is Missing. - HTC Thunderbolt (Verizon) - Android Forums - HTC Community see the second to last post on page 4. "Says 4GB right there.. Also Its being reported by a well known android hacker/developer Scott Walker that the eMMC is 8GB however it is Formated to 4GB is SLC mode. So basically is a Mini-Raid. Because eMMC memory has a high Failure rate, its done in this manner so that failure reporting will be less."
So, they take an 8GB card, format it to 4GB to have less errors, then reserve 1-2GB for the OS leaving us with 2.5GB.