I'm just bumping this pre-Gencon 2012 thread because these rulings have yet to make it into an officially updated document and yet this thread is not stick-ied.

If I was to summarize my key takeaways on this:

Skullman and others can still pay costs for more than once a turn played abilities if they have a 'once per turn' wording but not a 'only playable once per turn' wording in their effect.

Reversals cards need to be passed (played) before the Reversal response is considered played and subsequently negate-able. Formerly the Reversal response ability had a cost that included 'revealing' the card from your hand.