The difficulty with doing an automatic update, is that different people use different configurations, and different bootloaders.
At the present time, I use Grub legacy. A script could be written to download Tinycore, and even add a new entry in Grub.
Some people use Grub 2.
Some use other bootloaders.
There are too many variables in the way Tiny Core is set up by different people, to automate the process.
This is how I have menu.lst setup.
title Tiny Core 3.5
root (hd0,0)
kernel /tc3.5/bzImage quiet opt=hda1 tce=hda1 home=hda1 noautologin norestore
initrd /tc3.5/tinycore.gz
title Tiny Core 3.4.1
root (hd0,0)
kernel /tc3.4.1/bzImage quiet opt=hda1 tce=hda1 home=hda1 noautologin norestore
initrd /tc3.4.1/tinycore.gz
title Tiny Core 3.3
root (hd0,0)
kernel /tc3.3/bzImage quiet opt=hda1 tce=hda1 home=hda1 noautologin norestore
initrd /tc3.3/tinycore.gz
This makes it very easy to install the next version.
It would also be very easy to automate the update process with this setup.