I wouldn't like it, but you can understand why it might have to be considered. T20 gets the crowds, 50 overs has had a bit of a revival. Test cricket is the pinnacle of the game, but doesn't always get bums on seats. It will be increasingly difficult to sell a 5 day game, which might not yield a result, to a modern audience used to instant gratification in everything they do.
****ing ****ing **** ******* Some of the best tests I've seen have lasted the full 5 days, not necessarily all play, might lose a day due to weather, but many have been decided on day 5 with the drama at its apex. Five days is how much it takes if it doesn't finish in four or very occasionally three. You'd get so many draws. Imagine the situations we see so often: a team so hopelessly up against it knowing they've to bat out two days to save the game. Take a day off, bat out the draw quite comfortably. I suppose what really annoys me is just the fact that some newly appointed "somebody" is looking to make their impression on the game which has worked perfectly well for hundreds of years before they came along.
I think the suggestion is that they play 105 overs per day - under lights if necessary so that's 420 overs minimum instead of 450 now. Obviously, the loss of a day due to weather will have a more dramatic effect. The motive is to generate interest. Personally, I'm not sure 4 days instead of 5 is much of a change. What is needed is the regulation of pitches to ensure we don't get 600 plays 500, then 200-2 dec and a tame draw after the team batting 4th bats 70 overs for 160-3. In English conditions, most Test matches are decided in 4 days anyway - many in 3. In the subcontinent though, bowlers need a better chance on flat, slow pitches.