You can easily move from 0.2 to TFS 1.0 without having to start over. Because of the compat.lua TFS 0.2 scripts also work on TFS 1.0.
TFS 1.0 is faster than TFS 0.2, has all kinds of extra features and functions and several bugges from TFS 0.2 are fixed in TFS 1.0.
TFS 1.0 is based on TFS 0.2, so almost everything from TFS 0.2 is possible on TFS 1.0.
It's also still being developed, bug fixes and new things added.
TFS 1.0 doesn't have SQLite, plain passwords and an Account Manager like TFS 0.2, but this won't be needed since you can just use MySQL, sha1 and a website.