Are we using MemoryCache for SimpleContent pages? And if not, should we?

[CrispinF]

cloudscribe already uses MemoryCache for certain page elements such as the Navigation. The cache is busted when anything is done to change the menu.
We need to check whether we're already also using MemoryCache for SimpleContent pages, to avoid every SimpleContent page request hitting storage. If we are not, we should consider whether to introduce this to reduce load on database, particularly under heavy load or DOS attack.