He doesn't really seem like he knows what he is talking about in that passage, so I don't think this means anything.
We pick up a soul gem here, which can be used to power up spells or create new ones. We didn’t get to see how this actually plays out, so sorry magic lovers. You’ll have to wait a little bit longer to find out more about this particular feature.
There are three possible explanations:
1. Todd or whoever was doing the demo explained what the soul gem was used for when he picked it up. The dev told the journalist in Skyrim soul gems can be used to power up spells or create new ones, but didn't show them actually powering up or creating a new spell during the demo. Clearly this means soul gems are used in a new way in Skyrim.
2. The dev did not explain anything about the soul gem and the journalist completely made up the part about using soul gems to power up spells (not possible in Oblivion) and create new ones (not possible in Oblivion).
3. The dev told the journalist that soul gems can be used to power up spells or create new ones and the dev was wrong.