The risk is FUDdy, but not entirely imaginary. In particular there's the thread of a threat of patent lawsuits from a variety of players in the industry. Of course, that's always the case in this industry, so I don't buy it. But RH might, and that's their call.

My guess too is that if Canonical manages to go a few years without a lawsuit from kernel copyright holders then we might see more of what it is doing. But RH would -I guess!- still suffer from patent FUD and so stay away from ZFS.

That's all fine by me. The better for RH's competition. More competition, mo' betta.