I agree with Matt on this, that SIP (Session Initiation Protocol) being embraced by Cisco is going to bring a new revolution, is a very good move and will help them in crossing all boundaries. Reason for this is that SCCP (skinny client control protocol) is their proprietary and works only on Cisco products. But SIP works well on heterogeneous products be it from Cisco or any other manufacturer. SIP is also faster as compared to SCCP. So by all means SIP gradually will take over reigns from SCCP and surely is going to open up new avenues.