The fallout from the Rubicon announcement seems to be three fold.
1. Owning high security space customs offices (POCO) is a bad idea.
2. This is another expansion/update which greatly benefits the large power blocs.
3. The expansion is a bit light at the moment of content.
Firstly here is the Dev Blog with more details on the high security customs house ownership.
On the one hand I think the change from NPC ownership to private is a bad idea, it hurts the smaller player. One the other hand it will be a cause of conflict and will force relocation, of PI or players, which can be seen as a good thing.
Your options are to stop PI, move your PI operation, own the POCO yourself, or make your ISK in other ways. Adapt or perish.
However I've been talking to some people in game who are deep into PI and they are quite concerned their income is about to get cut off. The main thought is a large power bloc will destroy the Interbus POCO's and anchor their own, raise taxes and manipulate the PI market.
This is Eve Online, these things happen.
We do not want people to leave the game because of it though, especially if they see a large alliance just juggernauting through empire space.
Example. Lets use a name like "Goons". If these "Goons" remove the local Interbus POCO's and raise their own they can then set the tax rate. Now if they set the tax rate at a high amount few people would bother exporting via the launchpad, they may try smaller container launches via the command center, and thus not much ISK would be made by the "Goons" compared to the time and cost replacing the POCO's.
However it is now quite expensive and difficult to remove that POCO as the new war declaration rules now apply.
As you can see from the above graph the costs are not to be trifled with. At the member count today of Goonswarm Federation (10880 members on 02-10-13) the war declaration cost will be about 700-800 million ISK, certainly quite an ISK hit to hopefully remove some POCO's and reduce the tax, which of course could be reversed immediately using the same mechanic but at a much reduced cost by the large bloc.
It's not a very good mechanic.
One suggestion would be a cap on the number of POCO's any once alliance can own in high security space, perhaps the units have a running cost or a tax on the tax multiplied by the number of POCO's owned. This could be seen as an anti monopoly measure by the various governments. Certainly the different alliances could then own many POCO's but they would be more vulnerable to war declarations as the costs would be more realistic.
Another one could be once the new owners change the tax rate, it changes slowly. For example the POCO corp tax rate is currently 0%, the high security tax rate is 10% (this will stay the same unless you train a skill only recently announced). Once the new owners change the rate from 0% to, lets say, 40%, the rate changes at a smaller amount per day, maybe 3%. This gives the current PI users time to offload their cargo, look for other places to more their PI to, and/or complain to their new landlords.
Finally, the Rubicon content announced so far for this expansion seems to be rather light on, I'm hoping some more features, some great features, are also due as it's feeling more like an update than an expansion at the moment.