Please don't forget that there are also closed source applications from OVI that might not work with new version of GLib. I don't know if that could also affect WebOS games.

In my opinion, a complete move to a newer GLIB which breaks ABI and API compatibility is completely useless. We need to keep actual GLib and use new one only for rebuilt OSS packages using either naming or LD_LIBRARY_PATH tricks (please check this useful post)