While Volition is busy hammering out the expansion for Saints Row The Third, it seems that they are also working on Saints Row 4.
At least, that is what one of the developers on LinkedIn has hinted toward. Supernnaution tweeted about it last night, specifically saying, "Saints Row 4 apparently coming to current-gen platforms as well (and PC, of course)." If you visit the developer's LinkedIn page now, there is no mention of Saints Row 4, which isn't that big of a surprise.
The moral of the story is that devs and pubs need to be aware that Twitter and Facebook aren't the only realms for media stalkers. People do stalk your resumes on LinkedIn.