It seems to me the main argument in favor of using liquid threads is to make it easier for new editors to communicate. While I agree that Wikipedia needs to attract new editors, I still have to question this rationale. I think (and I may be wrong), that a communication system that makes discussion more "forum-like" might be encouring more new editors to contribute to Wikipedia. But I also think it increases the desire to use the system for non Wikipedia related discussions. At the very least, could someone (and yes, this might be called stupidity or ignorance) point out to me the key points that are considered the benefits of this new system?
Topic on Talk:LiquidThreads 3.0/Design
Inviting people to have more discussions around articles and wiki projects is an important goal in itself. The idea that we should try to stop people from "using the system for non-wikipedia discussions" is outdated, in my opinion.
Having conversations in, around, and inspired by wikipedia is a great thing for us to support. and all of those conversations will in the end contribute to the breadth and quality of the encyclopedia. the same holds for wikisource, wiktionary, and other sister projects.