Greetings --
No, not really.
Like WinXP's built-in firewall, NAT-capable routers do nothing to
protect the user from him/herself. Again -- and I _cannot_ emphasize
this enough -- almost all spyware and many Trojans and worms are
downloaded and installed deliberately (albeit unknowingly) by the
user. So a software firewall, such as Sygate or ZoneAlarm, that can
detect and warn the user of unauthorized out-going traffic is an
important element of protecting one's privacy and security. Most
antivirus applications do not scan for or protect you from
adware/spyware, because, after all, you've installed them yourself, so
you must want them there, right?