David Morgan, the ICC president, has hinted that Test cricket may be reduced to four days to protect and enrich the game's oldest format in the face of lucrative Twenty20 leagues like the IPL. The suggestion comes in the wake of a few other changes that are being mooted, including a two-tier format and day-night Tests to attract more crowds
ICC chief suggests four-day Tests | Cricket News | Cricinfo ICC Site | Cricinfo.com
I think four-day tests are not going to do anything to liven up a dull test match. In fact, its going to increase the number of draws more because you have lesser time now to bowl out a side than before. If at all the ICC could do something, they should put in place a system where sides that push for victory are rewarded more than sides that try to draw a game.
The two tier system works for me because it would let the competitive sides clash more. But maybe they should let the lesser known sides (on the 2nd tier) to work their way into the higher tier based on their performances. I personally welcome this move (even though it might hurt nations like Bangladesh, Zimbabwe, etc).