I like this thread a lot. Very interesting ideas being tossed around.
My $0.02:
Checkdisk is not the same as a hard drive test, purely a check of the file system, which can become corrupted for any number of reasons, only one of which is hardware failure. For this reason, even if an automated chkdsk is implemented, we will need a separate hardware check. That's where I think @IanAlexander is going with doing a SMART diagnostic, which may be the best we can get for an in-OS (vs. bootable) hard drive hardware test (on the mounted OS drive at least).
Additionally, the chkdsk would have to be run without /f or /r so it wouldn't actually solve anything, just serve as an indicator that a run with /f or /r is required. (That would require to be run on a reboot)