jwatte:
It's my experience that you should never use dynamic memory allocation (operator new, malloc, or things that use them) on microcontrollers. There's just too much that can go wrong with fragmentation, heap running into stack, interrupts, etc.
I have seen that usually the bugs and issues tend happen in the freeing of memory.
So using things like malloc() tend to be ok for memory buffers that are never released.
--- bill