Guest Cache: No.
APC: Yes
WOL: Yes
vBulletin 5 Connect features an extremely powerful cache integration system that's very customisable - letting you choose what cache type (Fast, Standard & Long) goes in what cache type.
A typical scenario is to cache Fast and Standard variables in APC, and Long in the DB.
vB5 caches almost everything and it's a system we're going to leverage for our mods as well, as seen in InfoPanels, AUT and APTL that have already been converted.