On May 13, 2011, SpinMaster (The company that owns Bakugan and all copyrights) released this post on the Dimensions website and the Bakugan Forum:
On behalf of the entire Bakugan Team, we would like to thank all of our Dimensions brawlers for logging on and battling online with us. We hope you have had as much fun playing the game as we have had. On June 30, 2011 at 10:59PM (PST), all servers will be shut down permanently. The servers will be functioning as normal until this time and we hope you will continue to enjoy the online world of Dimensions until then.
We hope you are excited about the new season of Bakugan and all that it brings Ė from the all new Mechtogan, Mechtogan T.itans, and BakuNano to Die Cast Bakugan and to the stuff we havenít even announced yet!
We look forward to the next chapter for Bakugan and we thank all of our loyal brawlers and fans who will continue to Brawl On.
Donít forget to visit Bakugan.com for all the latest official Bakugan news and updates.
The Bakugan Team
There has been no reason to this as of yet, though there are several speculations.
A popular one is that Bakugan Dimensions is ending for good, but a worldwide online Bakugan game will be put in its place (Bakugan Dimensions was only able to be accessed in America and some parts of England). This would come about because of Bakugan making a new online game in Japan.
Another one that is almost just as popular is that SpinMaster's new series "Redakai" (A series based off the Mechtogan shown in Season 4) will receive an online game, and Bakugan will be shoved to the back of SpinMaster's mind.
Thousands of Bakugan fans, not only in America but around the world, are majorly angry at SpinMaster, mainly because they don't have a reason as to why it's closing. I myself am among them.
This does not mean the downfall of the game itself, they will still make new Bakugan, Mechtogan, Mobile Assaults, BakuNano, and episodes for as long as they dare to try.
I will continue to post as new information comes to light.