Here you can find descriptions of the "DNS Changer" malware:
https://encrypted.google.com/search?q=DNS+Changer

DCWG is a group somewhat like the www.confickerworkinggroup.org which takes certain actions on the internets to stop infected computers from becoming complete zombies.

Visit their site or otherwise detect and clean a possible infection with anti-malware applications, and keep your operating system updated.

The article is poorly written and barely informative at best, but it is essentially a repeat of a press release so there you have it.

What will happen is that the replacement servers run by the FBI, which catch requests from infected machines and give proper responses will be shut down, leaving infected machines with no DNS, which means, essentially, no internet. Nothing OpenDNS can do about that - affected users simply need to clean their systems so that proper DNS server addresses can be set.