this might already be a well known thing but i myself discovered it yesterday. unlike 2.0.1, the 2.1 keyboard doesnt take its skin from the framework-res.apk. there is a whole nother app that feeds the looks of the keyboard called VoiceSearchWithKeyboard.apk located in the /system/app area.
so... heres how you spice up that keyboard for 2.1! first, go in to your /system/app area and find that apk. copy it and place it on the SD card. put it on your computer and and extract the files. open it up and go in the res folder. in there you will find a few subfolders. drawable-hdpi and drawable-land-hdpi are the 2 folders that have the images that skin the keyboard. open those up to make the image changes. make sure all images are saved as PNG files. once your done, make the file a .apk again and place it in the root of your SD card. once thats done, open up TE or ADB shell and use this code
Heres is a SS of the one I madeCode:su mount -o remount,rw -t yaffs2 /dev/block/mtdblock4 /system busybox cp -R /sdcard/VoiceSearchWithKeyboard.apk /system/app mount -o ro,remount -t yaffs2 /dev/block/mtdblock4 /system sync reboot
and here is my .apk if you like this one