WZ radar shows a weak circulation in the vicinity of the eye - yet the satpics don't show any from the last hour or two. The satpics are not very good on the VISAT images as it's in between frames, but am trying to locate other sources for a satpic. What you described is common on all cyclones/hurricanes and an eye emphasizes strong storm depth and cyclone strength/organisation. It's not unique to NT cyclones as they are in reality what forms within the systems worldwide of this nature. If it does not form an eye it just means that it has not intensified enough - if this system had a lot more ocean on its eastern side then in all probabitilies would form one, it's just a timing factor of the storm's development.
The cyclone is due to make landfall within the next hour and a half, 100kmh winds are being experienced between Darwin and Port Keats to our west and we've been having drizzly rain with the odd burst, but no gusts at the moment. Won't be long and most people have taken shelter.
Mike