Banned internationally and franchise but not domestically. It won't ever happen simply because of financial reasons. Way too profitable and players make heck of a lot of money as well.
I find it boring to be perfectly honest with you. It's not really cricket, is it? Neither is ODI but at least in 50 overs match you get more entertainment out of it. Lot more drama, twists, upsets, heartaches, tears and so on.
Having said all that, I think domestically T20 may be a good opportunity to find some explosive batters. Apart from that I don't think it should be served as a source of entertainment for anyone, especially youngsters.