IPL T20 had a big part in India's rise in World Cricket in recent times (Doubters will say it also messes up your longer version playing mentality). Young players got to learn how to play under pressure under the spotlight! They played with and against top quality players from around the world. They were trained by the Worlds best coaches-specialized ones for bowling, batting, fielding etc.
A Bangladeshi style IPL or BPL will definitely benefit us. Its not always that younger guys like say Nasir Hossain gets to be in the spotlight and play under pressure in a big match with the whole country watching. Provided we can run this series regularly, bring in good coaches and foreign players we will reap benefits.