For the feature suggestion, see this thread:
Live Mesh Beta: Suggestions - Go cast your vote!
As for when more storage will be made available, that's not been announced, nor is it likely to be announced until it happens. I do expect that we will see more, but I'm not sure it will be as much as you are getting for the paid service you are currently using. Perhaps when this is a released product we'll see options to purchase more storage, but that's only speculation on my part.
-steve
Microsoft MVP Windows Live / Windows Live OneCare, Live Mesh, & MS Security Essentials Forums Moderator