I just commited the gio code into glib:
185 files changed, 52768 insertions(+), 8 deletions(-)
This is a pretty large piece of work. Its still got some areas that need work, and the docs are far from ready, however the API is imho pretty powerful and easy to understand. If your app uses file I/O in any way, please take a look at the GIO APIs and give feedback.