If you require to manage a different Virtual Data center with long distance and latency, now you can consider the alternative management tools beside viClient. vSphere 5 come with a new features call vSphere web client. Which allow you to perform the basic administration from the browser level.  It does not allow users to launch the virtual machine console from the web client.

Below are some of the screen shot to share

vSphere 5 Web Client

Option to select vSphere web client for vSphere 5

vSphere 5 Web Client Option

Configuration wizard for web client

vSphere 5 Web Client Configuration Wizard

Screen shot on Web Client Management console