I just think an OpenGL wrapper would be a HUGE amount of work not reducing code redundancy, but increasing it. Especially if you want this to be useful for others you have to implement a lot of methods, abstract away window creation and peer handling, maybe implement different native buffer handling for the two GL libraries etc. etc.
I fear we will not see you here again, once you started this

Well, I would not want to implement everything. I would implement the part, that we need for xith and that's not too much. Of course, implmenting everything would be a lot of work. If anyone wants to use it for his lib and there are some methods missing, he would have to implement them. That's one of the resons, why I see this lib to be highlly dependent on contributions.
And I don't think, there should be an abstraction for context creation (for the first verion), 'cause this is too different for t least JOGL and LWJGL. Well, maybe it could be a task for a second or thirt version.
So you see, the work is not too much. I would at least want to start with it and see, if it runs out of sight

.
Marvin