I've posted a few times about what I believe are the random nature of viral events.  Research suggests that far from seaking out those that are different to us online, thus opening our world to new ideas, we instead tend to seek out those like us, thus limiting the spread of ideas.  In the following video, Kevin Allocca from YouTube, attempts to explain how he belives videos go viral.

In the video he outlines the three things he believes are key to sending a video viral:

1. Tastemakers
2. Communities of participation
3. Unexpectedness

These are not new ideas.  The notion of a tastemaker is a common one, and one that Malcolm Gladwell spoke about in terms of connectors, ie people that help to bridge social networks and bring ideas to a new audience.

The second stage sees the community participate in the video, either by making their own versions of it or by joining in the discussion.

The final part is perhaps the key to it all, viral videos tend to be pretty surprising, be they so unique we couldn't have predicted the creation of them, or so surprising that anyone else finds them interesting enough to watch and share.

So I still don't think it's possible to spawn a viral sensation on a regular basis, but it's some interesting grist for the mill.