Malphonse, not to worry. If you come from an experience with a p&s, you will be very satisfied with the lack of shutter lag of a DSLR, no matter which brand or model you choose. There is a shutter lag for sure. And there is a difference between cameras. But I dare say it is measurable in a laboratory but hardly percievable in real life.
So you can compare other things when choosing your new DSLR, and put the shutter lag question aside. You'll be very happy whatever you choose.