A welcome development
This particular case involves siblings (as of last week), but I suspect we'll be seeing a lot more of this kind of thing even among non-siblings - yes, even among current rivals - in the next few years. Among other things, it means folks like Isilon will be forced to compete on the basis of software quality instead of relying on custom-tuned hardware to give them an edge in performance comparisons. Bring it.
(Disclaimer: I'm a Gluster developer)