What I was wondering about are the incentives. With NXT it's very clear: Everyone who owns the currency, wants to make sure the forging is done right and the currency keeps value.
The split then creates a Bitcoin-like situation. Isn't that exactly what NXT wanted to get away from? The holder of the currencyNXT2 might care about the forgingNXT a bit... but with differences. forgingNXT2 owners don't really care much about about currencyNXT2. They support it in an more indirect way.
Does one of these currencies have more 'political' power? Is voting about tech aspects for example done on forgingNXT2? If so, is it not worrisome that the developers have 50%?
This might technically be a great change. But is the incentive part all figured out as well?
As I understand it, the main forging FXT chain will not support voting transactions, but the FNX child chain will support vote-by-FXT-balance. So we will have vote by forging power, and I assume such votes will help decide technical policy. All the FXT will be distributed. For the devs to hold 50% of FXT (ie, 50% of forging power) would be a problem for security even without voting, because they could use it to launch a 50% attack. They will reserve 50% of FNX, but that doesn't have the same security/trust implications.
It's certainly possible that some people will have lots of FXT and no FNX, in which case they'll have forging power without necessarily caring about the transactional coin. When we have many child coins, they might own those instead, and want to promote them over FNX. Hopefully this competition will be healthy.
Unlike Bitcoin, there will be no block-reward, so there's no big incentive to produce empty blocks. Forger's income will surely depend on people using one or other of the child-chains, so they do have incentive to keep at least one of them healthy. Also unlike Bitcoin, forging doesn't require a massive investment in hashpower that will quickly be made obsolete by Moore's Law. Hopefully that will give Nxt 2.0 forgers a longer-term outlook than Bitcoin miners.
I can certainly imagine a world in which, say, Russia has one child chain and America manages another, and each uses their forging power to cause problems for the other. (Or maybe it will be a Christian chain and a Muslim chain, or a Mafia chain and a Yakuza chain, or a Google chain and a Microsoft chain - replace with whichever power blocks you want.)