I'm not sure it would be possible to do either of these but I would love to see this functionality:

1) Google Docs integration: Allow an attachment to be opened in Google Docs and allow it to be viewed and edited. Obviously it would be a web-portal type application. Not sure if it would be possible but throwing it out there

2) XMarks support: Right now I sync XMarks to my own HTTPS server. Would it be possible to create a client that would take the .json bookmark file from my server and sync it to Pre's bookmarks?

Both of these apps would be great donation-ware or pay-for apps.