Although that libclicd thingy looks outdated and/or incomplete, I like the testapps/list_platforms.c utility. It would be nice to have something like that in (a possible) wrapper ICD loader package (the /usr/lib/libOpenCL.so).
AMD has a similar (more verbose) utility called 'clinfo'. I have experimentally removed the /usr/lib/libOpenCL.so file from the Intel sdk, installed it alongisde the AMD sdk and tried what these utils would output. The result looks quite nice, see http://codepad.org/NGaPsYbr
I've just written such a library to print available platforms and their devices. Here's the output of it on my Q6600 cpu: https://gist.github.com/1069813 This is "just" a library, but a simple main() that calls its .Initialize() could print this easily. I'd wish to release that library as opensource at some point. Maybe this could be a nice time for it ;)