Yes, Cisco/Linksys has had problems with GPL before. From what we heard from the tech industry when that scandal hit (2003-ish), Linksys was borrowing freely from GPL and but not attributing it, a definite no-no. When Cisco purchased Linksys in 2003, they had a source code review and discovered the "oversight". After the obligatory "WTF do we do" meetings, Cisco decided to release the firmware into the open source community. This is why Linux hackers latched on and upgraded their router into a $600 beast.
Cisco is in much the same situation now. Linksys, their devision that made the iPhone WIP300, has borrowed from the GPL without attribution. What does this mean? Well, if Cisco is going to release the firmware for the WIP300 iPhone, that means open source coders are free to hack it to do whatever they want.
The WIP300 is a SIP phone, which is an open source standard for VoIP popularized by SIP VoIP provides and the project "Asterisk", which lets you roll your own VoIP at home with just a linux box. But if hackers get to this phone, they could possibly load it up with Skype, Google Talk, or MSN as well as SIP.
In any case, we look forward to Cisco's next step.