4 fan connectors on the in built fan contoller and most motherboards have 2 or 3 headers so you can run 6 or 7 fans easy. Could also buy fan splitters like these http://www.overclockers.co.uk/showproduct.php?prodid=CB-013-AK&groupid=1929&catid=153&subcat=

Does anyone know if this case will fit the Corsair H100?
Yes it can, but in push or pull only configuration. Fans will have to be mounted on the outside of the case (below top mesh) and the radiator on the inside.
In terms of the H50 in the 600T I take it I can mount a push/pull all on the inside of the case?
Yes it can, but in push or pull only configuration. Fans will have to be mounted on the outside of the case (below top mesh) and the radiator on the inside.
You can get the mesh/window for the black case as an extra, cost me about £20.
My old case had a window, and to be honest, I probably looked through it twice in the five years I had it. Pointless things. Bought the extra side for the mesh to stick more fans on, swapped out all the rubbish corsair fans, have an uprated 200mm fan in the front, 2x120s up top, 4x120s on the mesh, and changed the 120 at the back for good measure.
The white obviously already comes with the mesh/window pack and has upgraded fans, which probably makes it worth the bit extra, but if your set on the black version, like me (hate white cases) its worth spending a bit on upgrading the fans.
Arent your HD's back to front?Looks good though.

Does that mean the fans won't be directly fed to the radiator i.e. sealed via the case so airflow through the rad is reduced?
Does that mean the fans won't be directly fed to the radiator i.e. sealed via the case so airflow through the rad is reduced?
Doesn't make much of a difference with me, check my pics out, have a push/pull config bringing air in through the mesh>fan>rad>fan, this is working well and my temps have dropped considerably since using this case.