I really don't see what the big deal with ads is. I mean it's an awesome app and they aren't charging for it... Also, if you are modded you can turn off the ads (although it still has the blank area). It's one little thing at the bottom, not that big a deal to me. I guess they could offer a paid version with no ads which I am sure they will.
In the meantime for everyone who can't stand ads, I would check out EStrongs File Explorer. It looks almost exactly the same and has the exact same features, and more, then Astro. It also has more UI options like displaying folders more similar to a computer desktop.