I remember reading at one point AWS(shudder) compatibility was a core goal of ...Cloudstack? the thing Citrix has or had.. and one reason they didn't join forces with openstack was because of that.
If this person is so gung ho on those APIs go use that platform. It seems like openstack has a lot more momentum behind it than any other private /open source solution regardless of what APIs it supports. If there's demand for support, someone(s) will make it happen(whether or not it's distributed with the "main" open stack code set is unrelated). That's usually how it works in open source at least.
not that I care either way, the thought of someone wanting to replicate EC2 is pretty horrifying to me. It's such a bad design for most workloads.