On a different note, Djokovic just confirmed he will be participating in Monte Carlo. So, top 4 seeds are:
Djokovic
Murray
Nadal
Berdych
It's not really much of a look-in for Djokovic. He has a final to defend and it's unlikely he'll go further given it's Monte Carlo. At least he has a chance to defend it, if he'd missed Monte Carlo through injury then Murray would have pulled ahead in the race.
It is an okay chance for Murray to start clawing ahead of Djokovic. He's defending 180 and Djokovic 600, and the difference between them in the race is 490, so for Murray, every little counts. On the other hand, the seeding is not as nice as it was if Djokovic pulled out, given before he might have faced Del Potro in the SF, whereas now he'll play Berdych or Nadal, both of whom will almost certainly beat him. Still, given his better seeding compared to last year, getting the SF seems reasonable.
For Nadal, it's vital he doesn't lose. If he has a poor clay season, he's in danger of falling as far as 7th seed by Wimbledon, which means he'll run into nasty people in the earlier rounds when the grass is most quick and he's at his most beatable. On the other hand, it's Monte Carlo, so he won't lose.
Moderate chance for Berdych here. He'll probably beat Murray on clay and he can really threaten Djokovic on clay too, just look at last year's Monte Carlo. Probably actually a better draw for Berdych than if Djokovic wasn't there, because then he could have drawn Nadal in the SF then. Could make the final, more likely just to defend his points from last year.
This is really Del Potro's big chance. He skipped Monte Carlo last year, and the gap between himself and Berdych is 365 points. If he gets F and Berdych gets SF, then he overtakes Berdych, if he gets SF and Berdych gets SF, he's only 5pts behind. If he gets SF and Berdych gets QF, he overtakes. Unlikely Berdych will do much worse than that, tbh. But yeah, great chance for Del Potro to try and get the 6th seed for RG.