Very well, and striped down kernels run on hardware with even less resources today (embedded systems) than 3.1 minimum requirements. If a platform has lost support, and there's sufficient money in it to justify it, you can always go back in time to an older kernel. What really sucks is when a platform vendor maintains their own tree and it gets lost to time.

The real pain is populating the userspace if you need more than just busybox.