SADFACE :(

Yoinked from sesskagura:

David Kaye, Sesshoumaru's dub voice actor, confirmed at TFCon that he is not going to be reprising his role in The Final Act. Full details are here. Still no word on who will be replacing him.

I can't get the link to work (looks like the board is being slammed), but there have been rumors of this pretty much ever since talk of an English dub began, so I'm not terribly surprised :-/

ETA: Starks broke/confirmed this particular rumor [Source]:

David Kaye not voicing Sesshoumaru for Final Act dub
Filed under: Chapters — Starks at 12:21 am on Tuesday, July 20, 2010

In a move that should really surprise nobody, David Kaye announced at TFCon that he will not be reprising his role for Final Act.

Over the past few years, David has pretty much retired from anime voice acting on moved onto sports, moving to California in the process. This development is a bit disappointing considering his intention to be a part of the dub as per a statement last July at Mechacon and does not bode well for the participation of other VAs like Willow Johnson (Kikyou) and Moneca Stori (Kagome).

I don't sympathize with the now-screaming Sesshoumaru fanbase, but I will admit that David Kaye is a great VA who was vastly underused.

Source: My good friend from GameFAQs and administrator of the "Behind the Voice Actors" website, Pokejedservo

Edit: Kelly Sherridan (Sango) remains the only confirmed voice actor.