Norvegian Magnus Carlsen take sole lead in Group A. He has 3 of 4 possible points.
At today round Loek van Weli and Vladimir Kramnik won their games Against Veselin Topalov and Pavel Eljanov. Both played with white.
Results (Group A, B and C):

Corus Wijk aan Zee 2008 A-Group 11th-27th January 2008
Round 4 15th January 2008
Carlsen, Magnus	- Aronian, Levon	Ѕ-Ѕ	Ruy Lopez
Radjabov, Teimour	- Mamedyarov, Shakhriyar	Ѕ-Ѕ	Gruenfeld Defence
Lйkу, Peter	- Ivanchuk, Vassily	Ѕ-Ѕ	Caro Kann
Van Wely, Loek	- Topalov, Veselin	1-0	Benoni Defence
Kramnik, Vladimir	- Eljanov, Pavel	1-0	English Opening
Anand, Viswanathan	- Adams, Michael	Ѕ-Ѕ	Queens Indian
Gelfand, Boris	- Polgar, Judit	0-1	Catalan
Corus Wijk aan Zee 2008 B-Group 11th-27th January 2008
Round 4 15th January 2008
Bacrot, Etienne	- Movsesian, Sergei	Ѕ-Ѕ	Queen gambit
Harikrishna, P	- Spoelman, Wouter	1-0	Queen's Pawn Opening
Cheparinov, Ivan	- Nepomniachtchi, Ian	1-0	Anti-Meran Gambit
Short, Nigel D	- Koneru, Humpy	Ѕ-Ѕ	Petroff's Defence
Sargissian, Gabriel	- L'Ami, Erwin	Ѕ-Ѕ	English Four Knights
Hou Yifan	- Stellwagen, Daniлl	Ѕ-Ѕ	Sicilian Defence
Krasenkow, Michal	- Smeets, Jan	Ѕ-Ѕ	Slav Defence
Corus Wijk aan Zee 2008 C-Group 11th-27th January 2008
Round 4 15th January 2008
Braun, Arik	- Van der Werf, Mark	1-0	Semi-Slav Defence
Caruana, Fabiano	- Reinderman, Dimitri	Ѕ-Ѕ	Sicilian Defence
Carlsson, Pontus	- Ruijgrok, Dennis	1-0	Ruy Lopez
Van der Wiel, John	- Peng Zhaoqin	Ѕ-Ѕ	Sicilian Defence
Li Shilong	- Negi, Parimarjan	0-1	Queens Gambit
Krush, Irina	- Grivas, Efstratios	0-1	Dutch Staunton Gambit
Ushenina, Anna	- Nijboer, Friso	0-1	Sicilian Defence