It is theoretically possible that the Devs cold expand the existing maps to 4x their current size (twice as big in both directions) as a "merged shard", move all the historical/event establishments to it, then do a housing scan, recording every house, its contents and its location.
As each area would be 4 times the area it was before, people would then log in to the new shard, and go to the area where their house stood on the old one, and would then re-place it, in that larger area, restricted in such a way as they couldn't block others doing the same from the other areas. After 3 months, any areas not reclaimed would become free for expansion, and any "held" homes not yet placed could be put any place they could fit. Of course, it would also mean people could have as many as 28 characters on that one merged shard.
It would take a lot of work, but it could be done.
To fix the housing issue once and for all (and it will have a down side) all they need to do is implement what they should have done long ago when housing was a REAL problem. This was suggested in the spring of 99 on CoB and may have been (memory is leaky) what lead to the Stratics request for Custom House Designs. I do not know if that isn still part of Stratics or got lost.
Create a Housing server.
House can be created on that server per account and for sake of argument have all the same rules as now.
Each house is instanced and can be of any size, number of floors etc. *Read as each house is ISOLATED*
Add the floor, tiles and add ons to allow one to build a Cave Home.
You get an object that will a) teleport you to your home on the equivalent of the steps b) Open a gate to your home on the equivalent of the steps.
Downside:
no neighborhoods (as in public, unless a work around fix of allowing a rune to be marked to the Steps to your house and your house has a defined public area (part of the steps construct))
no taverns (as in public, unless a work around fix of allowing a rune to be marked to the Steps to your house and your house has a defined public area (part of the steps construct))
no IDOC
Upside:
houses no longer place a load on the game server.
housing is no longer an issue, in terms of numbers of houses.
items in a house no longer place a load on the game server.
all of the game server land is available for PvP/PvM.
activities going on in the housing server do not place a load on the game server.
If your not on the House list some home, you can NOT go further than the equivalent of the steps.
Vendors can be placed on the equivalent of the steps.
The equivalent of the steps can be of any size and shape.
While I am against merges based on experience at EQ, this facilitates the reorganization of shards as the game servers no longer deal with housing.
Increased options and flexibility on houses. Not the least of which is the ability to directly allow Cave Dwellings by game design. A person wants to set up a 100x100 city for their guild, no problem as it is in the end only bits on a disk drive.
Remove all houses from cities (Luna etc) and convert the space to Vendor Stalls.