Recently, the team announced the release of the new 0.8 version of the game. The new release boasts a new network play feature as well as loads of new maps, several additional weapons and other upgrades.
The new network multiplayer option allows you to play online, as well as on a local network. A game such as Wormux really is most fun when you are playing a human opponent, although a quick match vs the computer is good too. If geographical distance isn't an issue, it was always possible, and still is, to play hot-seat at a single machine.
This new feature though eliminates that requirement, however. As with any network game, firewalls might be an issue, but as the game runs off a single TCP port, it should be trivial to add exceptions.
Anyway, the point is that these new additions make an already highly entertaining game a lot more fun. Blasting the characters belonging to someone across the other side of the world is now as possible and satisfying as a real-life opponent in the same room.
It's worth noting right now that for Linux users, the static binary download is still only at version 0.7.9, and doesn't benefit from these new features. However, you can download the latest source and compile yourself.
If you still haven't given Wormux a try, I'd highly recommend it. Downloads for Windows, Linux and Mac OS X are available.