First, FCoE and CEE standards are yet to be ratified. In theory, not much will change between now and ratification but they are NOT ratified standards. Most IT managers are not going to start deploying non-ratified equipment.
More important is understanding how the data center deals with change. Change in the data center comes at an expense measured in hard dollars to buy the technology and soft dollars to implement the technology. Adoption of new technology in mass happens when the pain associated with the current way of doing things is greater than those expenses. We saw that with server virtualization; it required money and effort to move to virtual servers but many customers feel that the effort is worth it.
I'm not convinced that we have reached that point with storage infrastructures. Do storage managers want more from their storage infrastructure and do they want to drive down costs while making it easier to manage? Sure. Who doesn't? I'm not convinced that FCoE early on will address many of those issues nor am I convinced that waiting will put you at a disadvantage.
What FCoE will address from the moment you install it is NIC and cable consolidation. That's it. Since most data centers will deploy FCoE slowly, very slowly, it will take some time for the positive effects of that cable consolidation to be measurable. The problem is the cost of the NIC and the cost of the CEE cable are more expensive, so any hard cost savings if not a total wash, will be minimized.