The television delay for "live" sports seems to be surprisingly high (and has got worse since the advent of digital TV); we're talking 5-10 seconds here. Probably even more for streaming video.
Would be interested to see a breakdown of how all the additional latency is added. I'm sure part of it is from the increased of overlaid graphics. The recently-posted article about the virtual American football firstdown line mentioned that they added a 2/3 seconds delay to accommodate the technology (at least, in the original implementation).