A thought just occurred to me.
Amid all of speculation surrounding Viz's upcoming announcement and the expectation of simultaneous Japan/US manga releases (either by volume or chapter), something critical has been overlooked. That something is the effect it would have on combating scanlators.
There are two answers and they depends wholly on the magazine the manga is published in.
For the sake of argument, let us assume that Viz licensed every manga published in Weekly Shonen Jump, Weekly Shonen Sunday, and Weekly Shonen Magazine.
In the case of Shonen Magazine (represented by Negima, Zetsubou Sensei, and Fairy Tail) and Shonen Sunday (Rinne, Hayate, and Kenichi), the effect of simulscans would be huge.
Yet for Shonen Jump (Bleach, Naruto, One Piece, Bakuman, Psyren, etc…) the effect would minimal to none.
The reason is quite simple. Shonen Jump leaks early, way early. I don't know whether to attribute this to Shueisha or to their distributors, but its been like this for years. Sunday and Magazine leak too, but only by a few hours and usually only just text spoilers and camera pics from 2ch, not full-blown chapters like Jump.
If you were to ask me, "Hey Starks! When does the new Bleach come out? You'd expect the answer to be Wednesday, but it's actually the following Monday for those who desire a legal copy.
Herein lies the problem for licensing companies. They can't break the street date. Therefore, Jump scanlators cannot be deal with until Shueisha and its distributors crack down on the leaks.
Edit: I stand corrected regarding Fairy Tail and Kenichi. It's not common for chapters of both to leak days early. Both series, along with the Big 3 Shonen Jump series are scanlated as part of the superhuman efforts of Manga Stream. I don't know how they do it.