@punx45 , I'm about to go almost the same way myself, wiring up buttons from my genuine arcade machine. I'm planning to use the grounding instead of the plus feed (Raspberry's GPIO's should trigger fine on three state i.e. either open circuit going high to feed voltage OR going low to GND).
However, my thought was also a prevention from involentary multi triggering but not by H/W support, we do have plenty of computer power at hand; have a look at this article Physical computing with Raspberry Pi. Some simple sleep timers should do it.