I think GfK might release European week one GTA IV figures this week, probably after NPD release NA figures.
From Meristation:
GfK ha anunciado que pronto hará el balance de qué versión ha vendido más en Europa y en el mundo, aunque al primer interrogante creen "tener casi ya la respuesta viendo las primeras cifras, (a favor de PS3) más igualadas de lo que se esperaban, eso sí".
Google Translation:
GfK has announced that it will soon balance which version has sold more in Europe and the world, but believe the first question "have almost already seeing the initial response figures (for PS3) matched most of what was expected , Yes. "
Link