Community manager Chris Faylor stated on the Gearbox forums that updates based on user feedback are "in the works for all three platforms." Along with some other fixes and additions, the PC update will raise Duke's weapon limit from two to four. Faylor didn't confirm whether or not the weapon limit would be raised on the Xbox or PS3 versions, saying that details on the console updates should be announced "as they're finalized."
Update: Sadly, it doesn't appear that the weapon expansion update will be coming to Xbox or PS3. In a new forum post, as reported by Shacknews, Faylor cited technical issues and noted that it is "unlikely that the expanded inventory can be enabled on consoles."