Ford put Escape Hybrids into Taxi Fleet service in New York, San Francisco, and Las Vegas. These cars got heavy use, about as heavy as you can get. Ford says these taxis went 200,000 miles in 2 years without any battery issues. Ford says the 2005 FEH has been more reliable than the gas only version of this car.
I still say ( and still expect ) the HV battery to be a lifetime component.
These batteries will last the lifetime of the car. ( Ford says 15 years )
I don't care what anyone says, after 15 years, (250,000 miles) the car is ready to be taken off the road.... for good.... not have a new battery installed!
The only people who
should consider the battery a "consumable" like oil and filters, is perhaps, taxi fleets, and persons who drive 100,000 miles in a year. But after 250,000 miles, does the car
look good enough and run well enough in other aspects to hold onto it? I mean, the carpet, seats, engine, won't last forever either?
I'm 99% certain that 99% of all hybrid batteries will last the lifetime of the car. Worry worts will always worry though I guess.....

-John