Sure it is, and it was time for the NL to do this a long time ago. Since 1973, when the DH came into existence and only the AL adopted it, the two leagues have been playing by two different sets of rules -- really, two different ways to play the game.
The AL plays a 10-man game, the NL plays with 9 at a time because the pitcher still bats. For me, the most persuasive reason that the DH rule should be used in the NL is that there are few things more boring and pre-determined than watching a pitcher try to hit. With very few exceptions, pitchers are an automatic out. Their typical contribution is to try to sacrifice-bunt a runner on first to second base. Drama? Uncertainty? It's like watching dry paint!
The DH admits this reality and uses the pitcher's spot in the batting order to try to create more runs, more offense. That's been OK with me for 40 years.
I believe that when the current commissioner retires after 2014, we might see the rules change, extending the DH rule to the National League.