Back in 2004, anime was airing on multiple television channels. The one channel that was on top was Cartoon Network with the Toonami block. On Saturday nights they had 3 solid hours of anime. When the late night came around the Adult Swim block started with 2 to 3 more hours of anime. 2004 was consider to be the peak of anime on television. Few years have passed and only Adult Swim and SyFy are the ones airing anime once a week at late night.
Well this is a bit of a complicated matter. It's true that if Dragon Ball Z Kai does real well for Nicktoons they could start picking up more anime but the problem with that is that Nicktoons still considers themselves as a kids channel. Meaning anything they would show would be either a show aimed at kids or a show that would be incredibly edited(ala Dragon Ball Kai).
While that would still help to draw in new fans it wouldn't really help people who wanted to see anime on TV because most of us would rather not watch a heavily edited for kids version of a show we love. There is the possibility that Nicktoons could do a Adult Swim kinda thing and air more mature stuff later at night but honestly if they haven't done that yet they probably never will.
I guess the way I see it is it's a good thing if it happens because it will create new fans. But for existing fans it's nothing to really care about because anything else they show would be in a format we would not really want to see.
I noticed Kai on Nicktoons. I think the reception will pretty much be a hit or miss. I loved DB back in my kiddie days, but now I facepalm every time I see it on American television.