I know, I wrote about Logos yesterday too.
But really, this is a big thing for us here at Logos Bible Software. Go to the Logos Mac page for more information and a download of Alpha 1.
This is an alpha. It is not a tested, tried and polished shipping version (or even a feature-complete beta version). That means don't do mission-critical stuff with it; be ready for crashes, halts, and incomplete feature implementation. If you don't want to install it (and please don't think you have to install it), check the most recent video of the application in action.
(Be sure to read the FAQ and the known issues list; also be sure to monitor the Logos Macintosh Newsgroup)
And keep your eyes on the Logos Bible Software blog; I'm sure there will be a formal announcement there sometime soon.