I'll tell you what I know:

i) In the krypt there are a few character parody images that take the form of an advertisment, kenshi's one shows him endorsing a box of novelty glass eyes, one is an 8-ball, one is a reptillian-looking-eye. And one is a clock, reading 12:43. There are a few others. (I forget which koffin number, check a guide or something)

ii) If you hang about in the krypt, you can hear a whisper saying "time's eyes will lead you to 'Saibot" it's not completely clear, but that's what most people think it says (or to some, just "time will lead you to 'Saibot"

iii) Thus... 'time' and 'eyes'. Where do you find time and eyes? in the aforementioned kenshi paraody.

iv) how do we take this? it could be a button combination (a1, a2, a4, a3), it could mean that you need to set your console's clock to 12:43, you may need to beat the game in exactly 12:43. I don't know.

It was revealed at Fight Night to be a joke, and the voice definently says "Time will lead you to Saibot". 12:43 is a joke, nothing more, nothing less.