So yesterday, VMware released the HTML5 vSphere Client as a fling, this is available for download here. I have put together a PowerShell script to deploy this to your vSphere environment.
It seems unusual for this to take the form of an OVA, but at least this means that it does not touch your existing vCenter, so should be deployable with less apprehension.
The client itself is issued an IP address from an IP Pool, and therefore has a different IP address to access from vCenter. Deployment of the OVA is pretty straight forward, and instructions for use and setup are in the link above.
There are already a tonne of posts around the features present, and not present, in the vSphere HTML5 Client, I am not going to go over that here, suffice to say, it is a fling for a reason.
This script (at first release) assumes that a valid, enabled IP Pool already exists in vCenter for the IP you allocate to the VM, I will add functionality in the next release to create an IP Pool if one is not already present.
Other than that, you should just need to replace the variables at the top of the script to use it for deployment. The script is available on my GitHub repository at this link.