The expansion beta was a time of great hope, in that the company encouraged the idea of their responsiveness to the fans.
It was a false hope, and when proven false, crashed the whole game and experience for me. All that I did there, and all that I thought I was accomplishing, went for naught. That was the nadir point of my entire gaming "career", the absolute lowest. I felt used and then discarded. It took the divorce of my PK protest to break me out of there. Thank goodness for PK's!
If ever there was an example of "misplaced trust" leading to anxiety, because hope is false and expectancy misplaced, it is that of Blizzard North in regard to delivering on their promises. For me, never again!
I concur with Occhi about the LL. In a functional sense it was at its peak during the beta, but in terms of community I think it shone more brightly at earlier points, and that it had already dimmed months before the beta hype. Nothing to do with the LL, even, but rather with the community in attendance.
Or... who knows. Perhaps in my absence, it has shone most brightly recently. I have stopped in only about five times in the last nine months.