This version is an update on 0.6.3 with a more strict exploit mitigation code. Users of 0.6.2 should either upgrade to 0.6.3.2 or downgrade to 0.6.1.
February 16th: Windows binary available, signed both with a code signing key and a GPG key. Note: there won't be a 64bit Windows binary for 0.6.3.2 due to a lack of time. The new network subsystem has significantly improved CPU and memory requirements so you shouldn't be running low on memory even with the 32bit binary.
February 17th: OSX binary available, only GPG signed, will be released code signed in the near future.
February 19th: OSX code signing delayed for a couple of days for technical reasons.