I know that French and American oaks have often been used to flavor wine. Are there any other types of wood that is suitable for this purpose?
In Japan sometimes Sake is aged in Cedar barrels, I know of some beer makers (Cigar City) who also age in cedar.
I'm sure other woods can/have been used for beer as well as wine but oak is the most dominant because it is particularly well suited to making barrels that won't leak.
From a home brewing/winemaking perspective there's nothing stopping you from experimenting with other woods in the form of wood chips. Apple wood might add a rather interesting element to a beer or wine.