Viz sent out a nice email and press release this afternoon in which they announced their acquisition of Inuyasha Kanketsu-hen.

This was expected to happen sooner rather later and shouldn't come as a surprise to anyone.

Of course, announcing so soon with a logo and such does lead to suspicions that Viz is planning a English-subbed simulcast of the new series.

Sources: 
http://inuyasha.viz.com/ 
http://www.therumicworld.com/series/inuyashaanime/

Edit 1: According to Higurashi of Inuyash Information from Japan and Patches of Inu-Goya, the anime is rumored to be only 26 episodes in length. I hope to god this isn't true since sane pacing and preserving as much material as possible would require 52 to 104 or so episodes at the very least.

Edit 2: YTV has put up their new Inuyasha website.

Edit 3: The DVD containing the Black Tessaiga OVA as well as the Ranma 1/2 and Urusei Yatsura OVAs will be sold for the equivalent of $150 to $200 in Japan. Ouch. >___<

(click to enlarge)

Anime News Network and 2channel can now confirm the rumor.

Inuyasha's back!

Inuyasha Kanketsu-hen (犬夜叉 完結編 Inuyasha Final Chapter)

This new anime will cover the manga material that the first anime didn't. This isn't a Fullmetal Alchemist: Brotherhood-esque rehashing though. Only volumes 36 through 56 will be animated.

Thank you to Rumiko Takahashi, Sunrise, Shogakukan, and Yomiuri TV for making this possible.

Edit: The DVD release for Inuyasha: Black Tessaiga, the Ranma 1/2 OVA, and the Urusei Yatsura OVA is January 29, 2010.

Courtesy of the Rumic World and Inuyasha Information From Japan blogs:

The Shonen Sunday #31 reveals that a big news about InuYasha is announced in #34 on July 22.
Generally speaking, this description means the 2nd anime series starts in October.

I'm a good friend of Higurashi, the webmaster of inu-yasha.org (IIFJ), and I am utterly shocked by this news coming from her. Not so much by the news, but how it was delivered.

Higurashi wouldn't dare make such a confidently worded announcement about a new Inuyasha anime unless she was close to 100% sure that it was a reality. I've known her for at least 5 years and I trust her conjecture on this matter. If she's wrong, I won't hold it against her. If not a new anime, the only other thing it could would be regarding the release date of the Black Tessaiga OVA.

I myself have long stood by the notion that the Inuyasha franchise (not counting manga releases in the US) would only be relevant for one year after the manga finished in Japan. Additionally, I have held that there existed a critical now-or-never window of opportunity between the Fall '08 and Fall '09 seasons inclusively, for a new anime or continuation to be announced.

After 5 long years, is this the news we've all been anticipating?

Edit: To the best of my knowledge, Sunrise has not scheduled any series for this Fall. A new Inuyasha would be the only thing they'd be working on other than the Gundam Unicorn movie.

Edit 2: It is quite possible that the news may leak on Saturday the 18th when the Shonen Sunday issue layout is leaked.