considering purchasing a touch, got a couple questions about the battery.

this would be my first foray into iPods since the iPod mini, which i bought about 3 1/2 years ago. the entire time i had it, the battery life was terrible (2-3 hours) and the battery tied entirely after 2 years (still works in the dock, but won't even hold a charge for 10 seconds). when i looked into replacing the battery, it was going to cost like 200 bucks or something, which is as much as the thing cost in the first place, so i decided to forget about fixing the thing and curse the fact that apple has never used replaceable batteries in the iPod.

now, i know (or at least assume) that great strides have been made in this department since the mini, as all the iPods out today are catastrophically superior in every department. people with more recent iPods/knowledge of the touch: how long (i.e. years) should the touch's battery last? what affect should moving to flash have upon battery lifespan? also, what is the current situation with replacing dead batteries? is it still a fortune? would applecare cover battery replacement?

thanks for any help.