Have you tried rebooting your device?

Are you booting from internal flash or SD/MMC - has the filesystem on the latter become corrupted somehow?

/lib/libc.so.6 should be symlinked to /lib/libc-2.5.so - has something deleted either libc.so.6 or libc-2.5.so? If so you may be looking at a reflash unless you can download the missing file from somewhere (I can put it up here if necessary).