Hmmm sound stressful decision :-)
Before u decide to get Nikon S4 I suggest u test it out first.
Ok, I don't own Nikon S4, but I did try at the shop to take same shots at 10x zoom, in order to make it less blur I set the ISO to 400.
Pls see the sample that I took:
Shutter speed: 1/35, ISO: 400