Beta 2 in April, beta periods take 3, 4 months minimum. Then, a RC
stage is entered, which can be pretty quick or can also take one or two
months, then it's released.
As this is a project of a huge size, a lot of factors can hold it up
and make it slip. For example, there is no real final beta for SqlServer
2005... just CTP's. So when it will be released is anyone's guess,
though with some math you can calculate that it won't be before October.