For those that don't know this site:

www.scifan.com

It's organised by series and themes as well as writers. Dab handy that.

I visit regularly to use their New & Upcoming sections. They've got a drop down list of upcoming titles by month up to November 09 as of today.

You can also sort by format to find new and upcoming ebooks. It's aimed at the US kindle readers, but I still find it useful to check UK supply for sony ereader too.

The site is updated regularly ... I can't recommend this site highly enough.