The question we have now is will the HP Gen 9+10 platforms support CX-4, or will we need to upgrade our 10Gb backbone to a newer installation such as fiber optic?
Don't think of fiber as newer. Fiber is still sub-optimal. You never want fiber until it offers you something you were missing... like distance or RF interference avoidance. Overall, copper is vastly preferred until it runs into a problem that fiber can solve.
Did some more research after I saw your comment and I would have to agree with you on this now. We will keep this in mind while thinking about our speed problems here. Everything is same rack or adjacent rack so copper should be fine.
I appreciate the input.