#1 - 2012/07/20 12:44:00 PMI haven't played the Beta despite having a key because I don't want to spoil the content of the expansion, however I feel that everybody else going to the beta is still going to hurt my experience on launch. Sure beta testing means we get a few less errors and bugs, but personally I would prefer it if Blizzard cleared up as many problems as possible using internal testing and then dealt with the "beta" issues once live.
When TBC came out there was a huge amount of anticipation and excitement about going through the portal and seeing what was waiting there. There were a few bugs and crashes but we were all in it together. Now it seems like everybody already knows what to expect there's no surprise and no figuring out encounters. I suspect I'm going to get into my first 5-man and probably find that at least 1 person already knows exactly what we all need to do. Maybe some people prefer that but I don't.
Also I fear that a lot of players will put so much time in on the PTR that they will already be burned out when the expansion launches, and be itching for the next one - which will inevitably cause some amount of drop-off.