There have been hardly any rumors about the upcoming iPod touch update that Apple will announce sometime in next few weeks. But today MacRumors posted that they have heard from a source that iPod touch will see very little design change. Arnold Kim posted:

MacRumors has received information indicating that the next iPod touch revision will be a very minor change, with the primary addition being the introduction of a new white model. Only minor changes are expected for the existing hardware, with the addition of an oleophobic coating for the display and a revised ambient light sensor seemingly being the main differences. Otherwise, we expect the models to be nearly identical to the current fourth-generation iPod touch model.

Rumors are Apple will announce the next generation iPod touch alongside iPhone 5 in October first week and it should ship soon after that.