Cisco has a stateful inspection firewall. And Sourcefire is a very good IPS. Taking an IPS and putting it on top of a stateful inspection firewall gives you a stateful inspection firewall on a very good IPS engine. It doesn't give you a next-generation firewall.
There are a number of companies, and I would put Cisco in this category, a number of companies are staring down the innovator's dilemma. The innovator's dilemma basically says that if you are a large company who has grown a good-size business with nice profit margins on an existing technology, then [you] are very, very hesitant -- if ever -- to cannabilize the baseline.
What they do is they keep the baseline and then they try to add to the baseline to approximate whatever the disruptive technology is. So I think Cisco's move with Sourcefire is very much in line with that.