SeedCode (http://www.seedcode.com) has announced FMChat for FileMaker Pro and Go. It costs US$329 for a site license.
FMChat lets you collaborate with your other FileMaker users right in FileMaker Pro or Go, sending attachments, images, and links to the records you’re talking about. Built solely in FileMaker 12, without plug-ins, FMChat is unlocked and scriptable, so you can change both the way it works and the way it looks.
Chat participants must be on your FileMaker network and must be using FileMaker 12 or the latest version of FileMaker Go. You can even runs scripts in your solution by clicking links in chats — approving orders, accepting invitations, or closing trouble tickets, for example.