Same problem. iPod Touch, 32GB, 25 months old. Working perfectly, listening to a podcast. Paused the podcast, got up to talk with a coworker, the iPod had 'gone to sleep' when I returned. Nothing unusual, with a one minute 'sleep' setting - this is the standard thing an iPod does. Except - now it won't turn on. None of the wake/home button combinations, nor any of the combinations to get it into firmware update mode, or plugging to a computer while holding down the home button with iTunes running. Nothing.
It still feels warm on the back when plugged in, which I assume is the battery being charged.
I brought it to the Apple store to be examined - they said it was dead, and they can't open these up and repair them like and iPhone. For $149 you can get a repair replacement, or get a '10% off upgrade' credit. With no 6th gen available, and 10% of the current list price of $250 - I'm not sure how a new 5th gen at $225 vs $149 for a 'repaired' iPod is worth it.
Any ideas out there for 'ultimate fixes' when nothing else works? Drop from five feet? Put in a freezer? Put in a sauna? Try and open it up and find a loose connection?
Brian