Well, it's been five years since this article was posted, and in all that time I have not heard a single person express the least desire to use /dev/kmem or express the least twinge of sorrow over its absence.
On Unix systems with free kernels, there is pretty much no safe way to use /dev/kmem in any case: too many details of kernel memory layout can and do change too often. Revving all the tools whenever you hack the memory manager would be appalling.
/dev/kmem was useful with proprietary Unixes before /proc and friends were thought of. These days, it is only of use to script kiddies: if anyone is still legitimately using it, it behooves us to take it away to encourage the poor self-harming sod to pick some better method, *any* better method of doing what he wants. Farewell, foul hack, you are not missed.