Yup, it's a really good dev build if you ask me. I wouldn't use it on a live server though because you never know what bugs lurk in the darkness Be sure to report any bugs if you find any though: http://forums.bukkit.org/forums/bukkit-help.6/
I am using it on my server. First big factions server that I know of that has updated legit (not that hacked crap people were using). I know there will be bugs but it is better than having an empty server in my opinion. 5 minutes after the update I had 15 people connect like yay And I updated my 2 plugins (simple though) to 1.4 waiting for approval
Lol well that's good, hopefully there aren't any major bugs that could ruin things for your players. Just be sure to keep an eye out! Well, can't really blame them for exploiting, it's human nature to take advantage of oppurtunies . Be sure to keep those bans local!
I have the build page book marked and literally check it every 15 minutes on my phone or laptop I am also on my servers too much (no life right now because I put my minecraft players > my life currently) because I love making my players happy