1.3 brings a host of changes, which you can find here: http://forums.terraria.org/index.php?threads/1-3-changelog.20617/
We're (of course) doing a Cheerful Ghost server. Join up here and play with us! http://cheerfulghost.com/Travis/events/79/terraria-1-3-server
The server will be launching soon, hopefully when TShock updates. If that takes a while we'll roll without it at first.