In other words start matches at 2pm than run into twilight/night.
Miller has brought it up on cricinfo and I think Boycott advocated it not long ago.
Main advantage would be it'd be great for people after work, would still be able to catch a session either at the ground or on TV and pushing the match into prime-time would significantly raise those figures. Also bad light issues, one of the most annoying things in the game, would become finally redundant.
The obvious drawbacks are the red ball under light issues and breaking with tradition (and watching the Ashes in England from Australia would suck ).