[adrianN]

I have a hard time imagining a programming language where memory layout of your data can be abstracted away like that. You need to think about which data to group together in memory and that depends on the access patterns. It's not enough to replace your binary trees with cache-friendlier B-trees if you still need to access half a dozen of them to perform one iteration of a loop.

[eternalban]

JIT for data, or an off-line simulation run pass for compiler could help. We'd probably have this already if it wasn't for the fact that unlike code, a JIT regime for memory can't be universally effective. So for the PLT part of it, maybe domain constrained languages? But that said, that all would bring into userland all the gymnastics that VM is doing with paging, etc. I think the more interesting question is what would an OS + language families that convey semantics/intent to the OS look like?