I don't think that people HERE have glazed over that fact. There have been quite a few threads and posts that have expressed extreme disappointment at what appears to be a lack of mutiple player tackling. I think many of us here(myself included) naively thought that it would be a given that this would be in the first 360 madden. I don't need to state why we thought this.
It seems clear that this just isn't a high priority for most people that play Madden, i.e. all those folks that aren't on OS and other madden specific web sites. You see that the Vision Cone has been removed as a default option for the User. I would imagine that the casual-user majority spoke loud and clear about how they felt about that feature, and EA got the message.
The masses aren't clamoring for gang tackling yet, so they feel no pressure to make it happen. Another possibility is that maybe they just don't have people talented enough to get the job done right.