It has been difficult to estimate the overall probability of a record breaking jackpot because the changed game does seem to have effected sales figures considerably. The assumptions in my last post on this subject have probably not been validated by events.
In order to meet or exceed Whitaker's jackpot, powerball would need to sell about $280M worth of tickets more than have already been sold.
The last three drawings of a jackpot advertised as being greater than $150 million (annuity), which ended with the winning of a $220 million (annuity) jackpot, sales averaged around $53 million. If this sales figure were reached by reproducing the average from that jackpot, it would take 5-6 drawings and 4-5 rollovers to meet or exceed Jack. The overall probability of that happening, given the high odds, is not all that improbable. It's somewhere around 35-40%. Although it's not likely, it is still very possible.
These impressions are all very tentative because of the untested conditions and could be wrong.
For the Christmas day drawing that Jack won back in 2003, the sales were $163.3M. Somehow I don't believe that powerball will have a single drawing like that in the future. However were a drawing with that many sales, there would still be around a 30% possibility of yet another rollover at today's odds.