I think this would depend on the wheel, if wheelset like Ksyrium the hubs are specificaly designed for them. On standard hubs they have to be drilled out (atleast on some) which could cause the hub to be weaker at the flanges.
The spokes themselves would be as strong I believe but you will be subject more to side winds and harder to replace if one brakes on the road since not all LBS might stock those spokes.