the only problem with T20 is that it has been seen as the financial saviour of the game and idiots like Stanford who were only putting their money into T20 games did not help the situation.
But this the leads to over-saturation as a result of financial greed and eventually the paying punters recognise when they are being ripped off. Players must love it - where else do you get paid more for actually working less?
There is some room for this version of the game as it nicely fits in to your average sports fans attention span, can be played after most peoples work in the evenings so fits in with TV schedules and it provides entertaining and close finishes for kids to gain interest in the game.
However, it does nothing for anyone if it becomes the be all and end all of the sport like some people think T20 should become.
Which other sports have gone down a similar route in order to bring in more money? I don't see football or rugby playing games over 15 minutes each way. Golf is still played over 4 rounds or 18 holes in its various guises, we don't have the one furlong sprint in horse racing or the 30m dash in athletics (in fact they go the other way and seem to invent longer distances to run). Snooker and darts may have one frame or one leg shoot outs on Sky but they are not proper sports anyway.
So cricket is almost unique (until other posters remind of others I have overlooked...) in re-inventing itself with the time frame of its games.