The are a couple firms that have the capabilities to read counterparty. Like rufus said, all you need is a simple app that relays the info that is already sitting on the fill server. The CME and CBOT should either completely remove this info or make it easily available to everyone, not just the big locals that can higher developers and work closely with their clearing firms.
Or locals that works / owns their own clearing operations, of course, quite a few locals on CBOT have their own clearing operation. CME already tried once to remove the Globex counter party field, and the proposal was reacted to negatively by the CME members (including the ibank I was with), and CME backed off and compromised by removing the counter trader tag (which most firms don't even populate, but TT does, at least used to, heh). The clearing counter-party field is absolutely necessary, since that's what each clearing firm uses to "net out" the clearing movements / cash with each counter party. See here: http://www.cme.com/trading/get/adv/11063.html and http://www.cme.com/trading/get/adv/11311.html