The web interface is quite nice, but it is also very easy to control a device via HTML skipping the web interface altogether.
For example, this request will dim a light to a set level:
http://<VERA_IP>:3480/data_request?id=lu_action&DeviceNum=<ID>&serviceId=urn:upnp-org:serviceId:Dimming1&action=SetLoadLevelTarget&newLoadlevelTarget=<level>
(Where <VERA_IP>, <ID>, and <level> need to be changed to the appropriate values).
You can also write a small plugin that will send out commands when something happens (right now I'm sending out xPL messages but you could take this code and in about 5 min change it to anything else you want). I don't think that Vera necessarily does that 'out of the box', but it is pretty simple to write a plugin, or just modify mine which will be posted and then tweak it as needed.
I think I almost have this figured out with xPL, not sure if that is the best way to handle messages between Vera and EventGhost, but it seems to be working.
EDIT: Just to be clear, you can do 'push' rather than 'pull' status updates now.