I'm very pleased with this news.
I also guess that if Sony is to switch completely their store to Epub, they will update the 505 to improve ePub rendering.
I am in the market for a second reader, this will simplify considerably my choice as all the new readers I was considering (Pocket Pro, Opus, Sony, etc. will be using the same format).
So my wife and I will be able to share our library.
Now I only have to wait for the reviews of all these devices
Now let's hope that tomorrow Amazon announce us that they will do the same