Re: stop the CIO from deploying Win10 enterprise-wide
I would seriously question the sanity of a CIO who wished to deploy Win10 now, particularly if they have only recently completed a desktop refresh; unless some a business profit centre can provide a business justification and rationale for the spend.
Yes have it on the roadmap and evaluate it, but I see no reason to deploy it anytime before WS2016 has been released to market.
I would use the issues with Win8 and Win10 as a justification to fund an IT project to explore the viability of alternatives.
However, if the CIO has been visited by top MS exec's then it is probably time to either look for another job or accept your fate.