Came across this article on here
http://news.zdnet.co.uk/story/0,,t269-s2109150,00.html

Having a fire wall in NIC is an interning idea but I don’t see it catching on any time soon.

“Firewalls built into network interface cards help offload work from the processors of desktop PCs, and aid centralized security”

Maybe it’s just me but with the current speed of processors who cares if the firewall eats up 10MHz

“Although Intel also has a NIC that does encryption-offload, 3Com business development manger, James Walker said that the 3CR990 is the first to include a firewall. The NIC costs $120 list price, and the embedded firewall is another $50 for each client. The policy server costs $1000. “

With those prices it’s going to be hard to compete with a $13 NIC card and a free software firewall.

That’s just my 2cents maybe someone who sets up networks for a living could offer more insight.