Not sure there is any issues at all. Unless the arduino team was to take your library and distribute the library into their standard distribution, where would there be any conflict/mixing issue? The standard arduino distribution contains very few libraries compared to the large number of arduino compatible libraries avalible on this forum, the playground, and of course out in the wild.
If you are just issuing your own library code to the community at large, for anyone to add to their sketch if they desire, I don't think it would make a bit of difference how you licence it or even if you bother to licence it at all?
Lefty