I think the secrecy on most things is pointless. Nobody’s going to steal our ideas, they only steal ideas that have already been proven to work (Minecraft, Wow, CoD, etc).
Letting people play as it is developed would allow us to improve gameplay and should be much better quality control. The only problem is that people might not like something in the initial release and then ignore it when it has been improved and the problem is no longer there.
You do have a point on secrecy regarding the story and other elements like that.
The thing here, though, is that we don’t release the beta and reveal the story and that sort of content. We release working, polished portions of the game.

This tactic is what Minecraft and Overgrowth have been doing, and it seems to me that it has worked out awesomely for both of them. The pro’s certainly counter the con’s compared to the traditional way of making games.

Usually, the traditional way is used for secrecy. People are afraid work and ideas get stolen and executed before they’re done with theirs, also, the big game companies don’t want anyone nosing around in their development progress. I also think that some players might not like what they would see when it becomes visible how their block buster games are sometimes made.

Errh anyways, awesome to see you guys trying out new methods of development!
I for one can’t wait to see updates about the work on the game, keeps me interested in the final release!

With things such as new weapons, units, maps or storyline, (in short; game content) secrecy can lead to anticipation of the update.