Visit the Carbonite forums.
To answer your question, though, yes. Carbonite is currently in working condition with WoW 5.0.4, but
ONLY if you update it with a patch that a fan has posted in Carbonites "General" forum. Please see
This Post to find out how to update Carbonite. Please be aware that it still has a couple of bugs, but it functions fairly well. Rythal, the fan that writes the current patch, is working on it as hard as he can.
Please note that if you currently have Carbonite 4.301 installed, all you have to do is download and install the patch. The link for the patch is in the post.