1 Me: With time rapidly running out for the major character I will be killing off permanently by the end of the year...
2 Me: ... it's time to release another titbit of information about the event.
3 {dramatic pause}
4 Me: I know who it is!

Dun duhn duuuuh!

The etymology of the word "titbit" is interesting. As best I can ascertain without access to a copy of the Oxford English Dictionary, the original form was "tidbit", from the Middle English tyd, meaning choice or special, and bit, meaning a small morsel. At some point the British converted this to "titbit" for some reason I haven't been able to uncover, and this spelling and pronunciation is now the most common in the UK and Commonwealth nations. The "tidbit" spelling remains as an alternative in use in the USA, although it seems to have been a relatively recent re-invention, appearing in the US only as recently as the mid-19th century. It's not that the US has preserved the original spelling, but that they have for some reason gone back to it after an intervening couple of centuries when everyone used "titbit".

There is some speculation that the (relatively) recent American change was prompted by a prudish desire to sanitise the language of "rude syllables", changing the potentially titillating (pun intended) "tit" for "tid". However, there doesn't appear to be any solid evidence for this as the reason.