I'd be less worried about tech sites - afterall, a single conference can overnight turn what was vague into something solid on that end. I think more important for Sony is that they solidify their plans behind the scenes, to publishers, soon enough that they can commit to a schedule for PS4 launch skus, if a release is going to happen next year.
If Sony is telling pubs they 'want to' launch next year (per Kotaku), but Sony's plans are still in flux or their preparedness in terms of tools and all that lags Microsoft, it's easy to imagine pubs being skeptical while considering MS on track, particularly from a resource allocation point of view. If Microsoft is being very clear, and is very obviously ready, pubs will be assigning resources to make sure their games are ready for that launch. If Sony is still hammering certain things out and/or dithering on commitment to a launch in certain territories in a certain timeframe, it becomes difficult to treat it with the same priority. If Sony leaves it late, they'll will be depending on their hardware affording fast turnaround time for launch SKUs once pubs get a very clear greenlight.