Ok, I know that flint and steel does not exist in creative mode, and know that the lack of fire working in previous versions prevented it but now that fire is out, you should be able to start a fire with lava, and have the fire activate the TNT, But now the reaction is the TNT simply just burns with no ignition.

I assume that this is just a lack of TNT explosions programmed for creative however still should be considered a bug.