How about a ‘potluck’ pentathlon…you do ANY 5 (or 3 or 4) of the 10 events (actually we should throw in TJ and Hammer for good measure) and no ones knows what they will be until the day of the event. There would be no set order (which would mean energy preservation could become a big strategy issue) and you could fit the entire thing in to a single day (which is one of the biggest problems with the decathlon). The unknown portion of it would make it like reality tv and could possibly open the event up to non-decathletes who could pull off an upset if the events chosen were in their favor.
I think there could be something to that idea. Could be even better with some more non-track events – kind of like the old Jeep Superstars competitions – That Dave Johnson won like 4x in a row.