Makes sense. Previously they turned around games pretty fast and with HD titles like Resistance they clearly ran into polish/balance/flow issues. I'm assuming that they've used their normal development approach, which would give them a fairly playable end to end title already, but this time instead of a quick final polish and out the door they're taking time to really polish properly.
For those interested, if you watch some of the stuff on their site it's amazing how late they were trying to complete R2 prior to launch - for example the Stalkers that worked perfectly in R1 weren't working in R2 until just a few weeks before release and even then were actually inferior.
I think R2 taught Insomniac a lesson regarding giving projects more time and accepting that HD titles simply can't be turned out quite as quickly as they did with PS2 titles - particularly FPS due to the highly competitive nature of the market.
Try to be reasonable... its easier than you think...
