We have already been making preparations for 1.5, and as a result, when we update next, there will be some features that have been removed, as similar features have replaced them. This is mainly because of some immediate fixes that need to be applied. Anyways, the features removed are:
TNT cannons
absorb chests (goes with interact current chest flag too)
NoMobCarts
They have similar features in 1.5:
Dispensers dispense live TNT
hoppers above chests
mobs are scared of rails
Please keep this in mind, and we're sorry if you were actively using these features.
In lieu of the update, our preparations will result in less time between when CraftBukkit updates and when we update. I know this is a praise to most. I've come up with a technique to reduce such times, and it happens to work very nicely. Thing is, the pre-release was supposed to be this week, but due to bugs, it was pushed to next week, so we have some time.