Thanks for the responses everyone, I'm leaning more towards the Sony at this point, but any final decision will have to wait until I can physically hold one or the other and try them for real. Unfortunately, as Andanzas mentioned that will probably not be until after the first of the year. I've looked at the plastic logic and it doesn't do much for me at this point, I'll probably look closer when more details are available.
gilgomez, for me the possibility of the app store is not that big a deal. If I get a reader it will be to read not to do anything else - well ok, play MP3s as well. At this point I can't think of any apps I might want - although that is only because they dont exist yet
Thanks again everyone!