I certainly think MM will break their own record first. Yes California will bring in a lot of potential winners, but that also means that the jackpot will rollover to a higher amount quicker.
Powerball will get there eventually. The only thing I think will be a problem is that it will take a lot more drawings to get to a new record. But if you compare the amount of combinations in the new PB with the total population of all the states in it, you will find the ratio to be very high compared to the new MM. This might be a good thing which will prevent someone from winning the jackpot and give them longer jackpot runs. Also, I dont know if they got rid of that stupid rule which restricts the rollover amount to only $25 million once they reach a new PB all-time high. If they didnt, forget about PB reaching new highs anytime soon.
When Florida decides to join a multi-state lottery, it will be interesting to see who they select. But if MM wont allow any new members, then I think the inclusion of Florida in PB will be very positive for it.