I lifted that link from Corelin, and he nicely summed up the gameplay implications that fleet represents, so I don't need to go there. But I have a few more examples:
The theme, if you hadn't guessed, was how godawful massive fleets look in big space fights. Compare that to this:
Notice the difference in the fleets? I think this is something that, long term, could use some love. Not necessarily now, but some sort of fleet formation component to Eve could make this look a lot nicer, and make AARs look a lot nicer than the current pile of crazy ships all sitting in space looking confused and ready to smash into each other.
That's all, just a random thought about blobs that has nothing to do with the actual mechanics, and everything to do with the visual presentation.