I think the question is, "Can NCM be installed on ESXi 5.5 Standard Edition" vs Enterprise Edition.
Good question. I think the consensus is still: Yes it can, but it is not officially supported, nor licensed.
Speaking with VMware engineers the consensus is that Enterprise or Enterprise Plus licensing is required for this functionality, but vSphere doesn't enforce that restriction should it find a lower license key - this is up to 5.5 u1 where we are today.
However, I haven't seen an update from Engineering or anyone else regarding the following statement by Nick Dyer:
Our vSphere installation MPIO vib actually installs two services - NCM (Connection Manager) and NCS (Connection Services); whilst it may appear to be working on the front end it's unknown whether the Connection Service daemon is running as expected; so in an example of an multi-array scaleout cluster having NCS not working as we expect could be detrimental. This is where Engineering (including Wen Yu and a few others) are trying to figure this out right now.
We are still running ESXi 5.5 Standard Edition without NCM due to the statement above. We are not running a multi-array scaleout cluster, but the statement doesn't specify if it might still be "detrimental" to use NCS with a single array.
You're right in your consensus; all Nimble services (including NCS & NCM) are fully installed and functioning regardless of the version of license found on the ESXi server itself (tested up to vSphere 5.5 u1). HOWEVER we do recommend that for VMware support purposes you only run these services if you have Enterprise or Enterprise Plus licensing.