Oh.. unfortunate if this is true..
http://www.ffxivpro.com/search/item?q=summer
Seems the swimsuits will be untradeable. I was hoping to save some for a male miqo'te and possibly female roegadyn.
Ah well. I hope we have the chance at them again next year.. (I loved how in XI if you missed out on an event item it would come back again next year.. along with new items sometimes. :3)