Tom Allensworth, the website's founder, stated:
"The method of the hack makes recovery difficult, if not impossible, to recover from. AVSIM is totally offline at this time and we expect to be so for some time to come. We are not able to predict when we will be back online, if we can come back at all."
It's possible Warrick could recover a significant amount of lost content, but I have not heard from anyone at AVSIM about it. Perhaps they are using it now as we speak.