I'm still using Warty right now, so I can't comment on the stability of the Hoary preview. From what I understand the stable Hoary release is scheduled for April. If I were you, I'd just wait a couple of weeks until it's ready.
On the other hand, if all you're planning on doing is running an Apache server I'd stick with Warty. It has been well tested and if you don't need any specific functionality found only in Hoary there's really no need to use it at all.
Good Luck!