Anet wont say anything yet because they are trying to build up some anticipation. If everyone is blogging on forums asking when GW2 is coming out then they know that their methods of passive advertising is working. Everyone knows that the BETA is coming out the 3/4 quarter of 2008 so you know there will be screenshots posted all over the internet by then even if anet attempts to restrict it. Don't get your hopes by thinking that you will be included in the beta because the chances are that they will only pick about a thousand people. 5000000/1000=50000 You only have like a one in 50000 chance of getting picked. Don't worry some screens will get leaked by then.
oh for god sake they aren't gonna say anything yet becasue they want to build up excitement. When they release some shizzle then it will sizzle until then let them be! And STOP making poxy posts specualting