Apple is being very successful in ths regard. The ambiguity in their marketing is genius, and it's even evident in this thread. Your anger will cause you to follow things even more closely, to speculate, and after all this hub bub, you'll feel an overwhelming sense of relief when it comes out.
OS X Lion especially got me, and all of Macrumors. At the time I wasn't a registered user, but the speculation ran like wildfire. By the time it actually came out, I rushed to my computer to install it. I believe that this method adds to anticipation way more than any release date. If I were the marketing director I wouldn't change a thing.
Also, as someone else stated, you don't want iOS 5 as it is now. I'm currently running it on the iPad 2 I'm typing on, and just a few minutes ago it wouldn't unlock. However, I knew this going in, and this is necessary for testing purposes. iOS is such an intricate mobile platform, and one that cannot be rushed. The fruits of this care for detail has been glaringly obvious even since the original iPhone.