Hi Marcia,
welcome to the Sony Reader fold!
I can't answer your question about when particular books will be available at the Sony store, but I've noticed new releases tend to show up within a couple of weeks of their general release (much better than when I first got mine.)
But, I also wanted to let you know that I just taught myself the conversion process suggested by
JWolf and it's really not difficult at all. There are 2 freeware programs to download, and the directions are pretty simple. It probably took me a total of 30 minutes this first time, from downloading and installing both software packages, buying the book, going (very methodically) through the conversion process and uploading to my reader. I'd guess that, without having to download and install the software and after getting past the learning curve, the process will probably take a couple minutes tops. And it's substantially expanded my available library. I'm a happy camper, indeed.
Just a thought in case you want to give it a shot. I've been waiting for "The Buried Age" to show up on the Sony site for months, and it's nowhere in sight, which is what prompted me to give this process a try. Worked like a charm. I've got the book cover art and everything. On my reader, it looks just like the books I've bought at the Sony store.
Whatever you decide, happy e-reading! :thumbsup: