Not sure, I'd be curious too and I'll add this question. If the Eneloop charger is not a trickle charger will it damage the batteries at all to leave them in say 24 hours after they're finished charging?
I picked up the Eneloop charger + 8 AA's a few months ago to use in the new Wii and since then I've ditched the 360 play and charge pack for them. Wonderful batteries, relatively long life, can be charged in pairs or fours, no complaints, and when the Xbox 360 finally goes bye bye I'll still have batteries to use instead of a charge pack.
Question as well, I picked up some dirt cheap Powerizer batteries probably two years ago or so and the charger died. Will it damage them/the charger to put them in the Eneloop charger and use them?