Yes, what ever did happen to this? It sounded interesting.
The biggest problems I see in doing a cluster is that 1) All the worlds in the cluster need to be represented, and 2) The authors need to be in touch with each other for any sense of consistancy, and the sense that the history of all these systems has affected the neighboring systems, throughout their history.
The other problem is the old canon issue. IMHO there are too many Traveller sources spread over too many versions of the game and too many years... it's hard to write something up without violating some canon write-up or one sentance comment somewhere.
What would be great for a landgrab would be for a Traveller Historian, with a huge collection of Traveller materials on hand, to set up the land-grab area in a spot without much canonical write up. He/she could also provide what canonical material has been written for the region and systems, so that the landgrab writeups are consistent with canonical material.
I have looked up worlds on the TML landgrab site, and they are often quite different from canonical sources... this makes them unusuable to me, for all intents and purposes.