I got my notification this morning too. Did a quick test run, and it is clear that some records are not (yet?) transcribed/available. I have ancestors from Great Chesterford, a village in Essex nr Saffron walden, and these records do not seem to be available. I guess the reason why is that the copies of the registers are very faint; I've consulted them on microfilm at Essex County Archives, and they were very very difficult to read.
So don't get your hopes up too much - suffice to say that most of my direct ancestors in other locations have been found within a thirty minute session.
JULIAN