Interesting concept Kai. I dont know what I think about leaving wort laying around for a day though, even if you keep it sanitized/covered. Its pretty similar to what I had in mind, except instead of leaving the wort in the pot I would keep it in the fridge at pitching temp (45F) in a fermenter.
I only use buckets (6.5g and 7.9g) so I was thinking of 1) pitching the yeast into 3.5 gallons of wort into the small fermenter, 2) wait 24 hours, 3) add 2 gallons of wort to the small fermenter, 4) stir up, 5) transfer the wort/fermenting beer back and forth to get it thoroughly mixed.