Because a good portion of the Internet seems to be exploding over it.
Yes, Black 2 and White 2. Not Grey. Not a new third version. Black 2 and White 2.
The only details so far are that they will be for the DS and feature the above Pokemon- new forms of Kyurem called Black Kyurem and White Kyurem respectively. Scans revealing the Rival, Main Characters, and a Gym Leader(girl with guitar) have also recently surfaced, as well as some other bits. These new versions will be released in Japan in June/July 2012, and in the U.S./Europe this Fall. And yes, this is very legit- here's the link to the official Japanese website.
So, are you excited? Are you enraged? Can you careless about Pokemon? Let's hear it.