I believe the FLIR T-Series 480x360 cameras use 640x480 sensors, so unless they developed a new 480x360 sensor then they're probably using a 640x480 sensor.
They do indeed use the 640x480 detector and yes they are hackable to the full res
They are based on new Linux OS and apparently the bits we'd want to hack are heavily encrypted!
Pricing will be around £6K for E75 with either a 42° or 24° lens and around £8K for the E95
FLIR have dropped the price of the T640 by £7K, which hints at a new model with a 640x480 detector. The T600 and T620 are also "By request" now, which further supports this.
Expect to see a number of the older E30-E60 cameras hit the used market at a good price!
I'm going to see if I can order one of these in for work to retire some of the older cameras we still use.