Four draws means everything is as it was, with Carlsen leading, Kramnik on his heels and the rest of the field eating their dust. Despite this, three of the four games were pretty routine draws, though probably not by choice.
The game of the day, both in anticipation and in the event itself, was Carlsen-Nakamura. Carlsen came out of the opening - a Slav turned into some sort of QGA-like position - with an edge, but made no further progress. Nakamura managed to equalize and then even obtain a slight advantage of his own, but his slightly inaccurate 38th move allowed Carlsen to force a quick draw.
Here, then, are the standings after four rounds; there are three to go:
1. Carlsen 8 (+2 =2)
2. Kramnik 7 (+2 -1 =1)
3-6. Nakamura, Adams, Howell, McShane 4 (the first three have drawn all their games; McShane has won one and lost 2)
7-8. Ni Hua, Short (-1 =3)
Round 5 Pairings:
Howell - Kramnik
Nakamura - McShane
Ni Hua - Carlsen
Adams - Short (a good grude match for UK supremacy)
Finally: the games, with my generally light comments, are here.