There was another chat with the LINQ development team yesterday. The specific subject was LINQ to SQL. The transcript is available online.
There are some useful pieces of information in there. One thing to note is that LINQ to SQL in Orcas is not there yet. In the December CTP, "LINQ to SQL features will be limited to basic query support". The December CTP will be available "sometime in December".
The next big step for LINQ to SQL is apparently the February 2007 Orcas CTP. After that will probably come the first beta.
The final release of Orcas is still planned for the second half of 2007.