I dunno.
I look at the magazines out there and nothing really grabs me. Dragon (I still miss THE Dragon) has maybe an article an issue of interest to me. Dungeon has had anything for me in years. I have seen multiple "All Systems" magazines (White Wolf, Different World, etc.) come and go, all of them dying due to being non-specific ("Gee, I only want articles on X").
The market is very fractured. Magazines have to be pretty specific to survive at the moment. Trying to capture part of the D20 market is going to be hard, given the strength and availability of Dragon and Dungeon, and if a company starts running a magazine featuring just the D20 material that company is putting out, that is splitting matters even further (little appeal outside of a very small group).
Remember, gamers are a very tiny market force. Keeping a magazine running on a regular basis is expensive and needs a fairly serious fan base.
I wish 'em luck, but I won't hold my breath.