Renewal rates will be the downfall of the new TLD's
Budgets are only so big and eventually the drops will come as domainers hit their limit for renewals.
Same thing is happening at CIRA with the .CA ccTLD, one can see the drops getting bigger as Canadian's decide to drop underutilized registrations.
One has to be so careful with increases, I would say .com is probably the most immune to the drops but others are quite susceptible to the public deciding enough is enough.
So the question all these companies have to ask is...
DO THEY HAVE A USER BASE THAT IS STRONG ENOUGH TO ABSORB YEARLY INCREASES OF A BUCK OR SO?
For instance, are their enough .ca's in actual use that CIRA can ignore how many are dropped monthly due to unaffordability?
If I look how many I am dropping across my 3 catalogues this year I stand to reduce my renewals significantly as I decide to focus mostly on my higher value domains. The renewals are biting a bit so now I use my webstats to determine traffic, no more blind renewals, that started to become an issue when the prices climbed higher than $10 wholesale.