I rather see neither of them in power.
The following might not be easy to follow for non-Dutchies, but nevertheless:
Yeah, he will. You might have noticed the small rebellion in their faction a few weeks ago. Add to that the fact that Lilian Marijnissen, daughter of Jan 'Mao Zedong' Marijnissen (Their previous leader who was both faction leader and party chairman) has been put on no. 3 on the list, despite having no experience on the national level. Roemer (their current leader) has been unable to give to them a national victory and, looking at the polls, it's very unlikely he'll win it this time. He'll resign or be voted out - maybe not directly after the election, but surely before the one after this.
Now, if you look at any possible sucessors, it's noteworthy that many senior MP's aren't returning or are unlikely to return. Harry van Bommel and Sharon Gesthuizen are both leaving politics. Jasper van Dijk, a senior and active MP on especially education has been put on place 14 of the list. Considering the Socialists are polling at anything between 11 and 16, it's not position that assures election. It's very odd why someone who has been active, succesful and an MP for over 10 years is put on such a low and unsecure position. To me, it's clear that the party establishment is paving the way for Lilian Marijnissen to take over. Maybe another MP will be faction leader for a few years so Lilian can built up her expertise.