While pretty much every other iOS device released since 2010 is getting iOS 7.0.4, the not-qualified iPod touch 4 is getting the same FaceTime call bug fix but in retro iOS 6.1.5 form (2010 original iPad had not camera, so no FaceTime).
And no, even if iOS 7 still hasn't won you over, you can't jam this update onto your iPhone, iPad, or iPod touch 5. Sorry.
You can grab it by going to General > Settings > Software Update on your 4th generation iPod touch, or by hooking up to iTunes over USB and hitting check for updates in iTunes. Let me know how it works for you!