Don't worry! You have lots of options. Here are just a few.
1) You could import book purchases into the Reader software and then connect the 950 and transfer them by USB. Once Sony transitions to Kobo as it's official store provider then books should appear in your Reader for PC/Mac library just like a Sony purchase would and you don't have to import those.
2) You could import book purchases into ADE and then the software downloads them into an ADE storage folder. You can drag and drop the EPUB book file from that folder via Windows Explorer / Mac Finder over a USB connection to your 950.
3) You could find the file from the ADE or Sony Reader folder and then import it into calibre library management software and then transfer it to your 950 with that software.
When the transition happens and you're ready, I'm sure somebody here will help you out if you have problems.
