If they seriously want to use technology to assist the umpires rather than the commentators there are a host of things they could utilise. The simplest of these would be laser lights indicating the line of the stumps, as with most laser levels outside, the beam is only visible through special sun glasses. The bowlers foot could also be monitored by lasers to assist in the detection of noballs. Throw in a couple of height ones as well for the square leg ump for such things as over waist full tosses, bouncers and such. But none of this would aid the broadcasters so are very unlikely to happen.