[throwaway32]

yes, it is heavily patched to support things like IPv6 (which the Apache foundation claimed was "impossible"). However, the code-base is getting a bit long in the tooth, a more modern replacement will be nice. I am curious however about how they are going to implement CGI with nginx, as tons of applications still rely on this.

[madhouse]

nginx supports FastCGI, and CGIs can be supported via fcgiwrap and similar tools, it works remarkably well, and configuration's easy.

[lobster_johnson]

Nginx is a well-engineered piece of software. The only problem, in my opinion, is that does not support loadable modules; any features you want or don't want need to be configured at compile-time, and those are only the official ones that are part of the mainline code. Third-party "modules" such as Phusion Passenger are essentially patches. Since Nginx has a modular architecture, those patches are admittedly very clean, but it's still a pretty ugly situation compared to Apache's elegant loadable module system.