As someone who's created few OT's myself, including the rather unwieldy Halo Reach OT, I mostly agree with the OP here. I think the OT is a place to provide all the basic information about a game, and/or links to where people can find what they want, in an attractive an organized way, as a way to kick off the discussion about a game and provide a reference for those unfamiliar with it.
I'm also a big believer in updated OPs, with news/updates at the top for those following the game (not to replace new news for new information, of course).
Personally, I think the recent
Skyrim thread set a pretty good bar in terms of content, organization and presentation. It's comprehensive without being bloated. My original Reach thread was a bit bloated, but I scaled it back over time in subsequent OT's. There's something to be said for restraint.
The Halo Anniversary thread I post tomorrow is one post, and is pretty compact, a trend I plan to keep up for all subsequent OT's. It's a fine line to walk between informative and overwhelming, and I think expanding the content beyond one post starts to cross that line, at least for myself.