There was a TV programme here (yesterday?) which showed that the technology already exists, that it works and that there is little, other than prejudice against it, to stop it being introduced.
Although I agree that the Lampard incident does give rise to more people coming out in favour of the technology, I have never seen why it isn't possible to introduce it, at the very least for games at this level.
One of the arguments I've read here is that it would mean football at the top level was different to the casual/amateur game. Not an argument I've ever bought, truth be told. Hawkeye gets used in a number of sports, Rugby Union uses video refs for contentious tries and so on.