I never accepted that Kai was 'cancelled' after the Cell Games, as some people tried to claim. I maintained that Kai was postponed. In 2010 I replied to a topic where I pointed out, with evidence, that Dragon Ball Kai was becoming a global phenomenal , like Dragon Ball Z is. 2011 saw Kai grow. Kai stopped broadcast in Japan at the Cell Games but I believe that there will be a Buu saga. However, the announcement of the new Dragon Ball Z film has altered my opinion, but I'll post my original thoughts first, with analysis, and at the end I'll post my revised opinion.
Dragon Ball is Toei's most successful international franchise, by far. Here's a graph to illustrate:

The overseas film income for Dragon Ball film (ie series rights) for the 3 quarters of FY (Financial Year) 2011 was higher than the entire (4 quarters) of FY2010. I am certain that Kai's success helped in the revenue growth for that period. The overseas film income for Dragon Ball was just over 30% higher in FY2010 compared to FY2009. Dragon Ball has the highest overseas film market for Toei:

Given how successful Dragon Ball is and how Kai has helped increase revenue for Toei, it'd be stupid of them to stop at the Cell Games.
Over the course of 2011, there were other, sometimes major, hints of the possibility of plans for the Kai Buu saga. Among them is the fact that no country has used the DBZ Majin Buu saga to try and 'continue' the story after Kai Cell Games. That, to me, is a major sign. There were theories as to why Nicktoons US didn't broadcast the Majin Buu saga and went straight to GT after Kai Cell Games, even though it wouldn't make sense to new fans. Some thought that they'd need to edit the Buu saga further, some pointed out that they'd need to take out the Faulconer music due to the litigation Faulconer brought on Funimation. I want to cover the latter point briefly.
Faulconer brought a lawsuit against Funimation which lasted AFAIK 3 years. The outcome of the case was that Funimation would have to pay royalties to Faulconer if they used the Faulconer Productions music on any TV broadcasts, however they don't need to pay Faulconer anything for DVD/Blu Ray releases. Now, if Funi decided they didn't want to pay Faulconer, they could've used the Japanese music on the edited Buu saga and supplied that to Nicktoons. The cost involved would be insignificant compared to the revenue that would be brought in, but they didn't. France didn't use Z Buu after Kai Cell.
Why? Because if US, France, or any other country used Z Buu to try and 'fill the gap' then that might potentially saturate the market and potentially reduce the demand for a Kai Buu saga. I think all the countries were instructed by Toei to not use DBZ Buu saga to try and 'continue the story' because they have the Kai Buu saga planned.
And, if less popular shows like Big O, Ultimate Muscle, Sonic X can continue overseas after 'stopping or being cancelled' in Japan. Then of course Dragon Ball Kai, which is not cancelled and is very popular, can continue overseas.
So why the postponement after Cell? I have a theory.
The Majin Buu saga sees the biggest shift in the series since the Saiyan saga. There's a brand new opening and ending. 7 years pass, which reflects the characters ages. The Buu saga introduces more new characters than any other saga and it also sees the biggest musical change since the Saiyan saga.
That, and the Buu saga has the most merchandising potential. Super Saiyan 3, Fusion, new characters. In terms of merchandise, I would say the Buu saga is the most popular.
Also, Kai helped bring in new fans to Dragon Ball all over the world. Toei only have a set amount of DBZ episodes to work so, so they probably didn't want to use them all in one go. Kai was consistently in the top 5 and always in the top 10 in ratings. Toei know they can rely on Dragon Ball to bring them revenue and ratings.
So, my original opinion was that Toei would continue Kai for the international audience, but they would only supply the film, sound effects and perhaps music. They would not record a Japanese voice track.
However, the announcement of a new DBZ film and the fact that it takes place after the Majin Buu saga has altered my original opinion. I now believe that Toei would produce a Kai Buu saga for Japan and the rest of the world, which means they'd record a Japanese voice track.
And, I want an Ocean dub of Kai Buu saga so I'm not giving up hope.
Toei probably wanted new episodes of Kai Buu saga being broadcast while the new DBZ film is being released. If Toei continued with the Buu saga straight after the Cell Games, it would be finished before the new film is released.


