Are there preset heroes in Might and Magic: Heroes 6?

There are preset heroes, but only if you play Heroes VI offline. When you aren't connected to the Conflux, you can choose from a list that contains a single Might and a single Magic hero from each faction.

When you are connected to the Conflux, you are restricted to your dynasty heroes and the factions they represent. However, as you finish the campaigns, you gain the heroes from those campaigns. I'm guessing (hoping?) that once you have finished all the campaigns you will have a might and a magic hero from every faction in your dynasty.

If I'm wrong, or if you want to play online skirmish or multi-player games right now (and be able to choose the faction you start with), you have to create your own hero for each faction.