When I only started with Linux-on-PDA hacking, I, as people usually do, combed internet for any kernel/initrd images which were marked as being for the PDA model I had at that time. In such way I picked up few initrd's, and after practically comparing among themselves, selected one for standard hacking use, like kernel testing. A bit later I augmented it by installing some missing stuff (like mc), and seeing that many people are not so thorough and searching the net, put it up for others' use. That's basically what I've been using since them and suggesting to others who needed environment to test some kernel feature with minimal userspace involvement.
Of course, that situation was rather ridiculous - using some random binary-only image instead of OE-built is not perfect at all, and I was just hoping that someone else would go for that. Well, with the latest changes in OE to facilitate creating efficient initrd/initramfs images, I finally got to this myself. So, here's now such image, codenamed 'devimage'. Consequently, recipe to build it as a complete image is called 'devimage-image.bb'.
Its purpose defined as: provide environment which by default runs only minimal userspace (busybox sh and dropbear now, to support different connection methods), but offers all needed "kernel userspace" utilities from udev to specific utils for ALSA, IrDA, Bluetooth, WiFi, etc.
At the current stage it's not as complete as that, so help with filling it right is welcome (caveat: size should be kept in mind).