It’s here! Okay, it’s not really exciting by comparison with the 8GB and 16GB versions of the fourth-generation iPod nano, but it’s great to finally have our hands on the considerably rarer 4GB model. (Thanks, Alicia Bankhofer, for making this happen!) As you may or may not have heard, something weird was going on with the capacities of the fourth-generation iPod nano. On September 9, Apple announced that the device would come in…