Presumably they made something interesting with nice design. The bar isn't that high--TechCrunch covers very early Web 2.0 startups. If you write to them, and your site is worth a crap and in an interesting space for them, they'll probably cover it. It does help to be in the Valley and actually run into a TC writer in person (they're all really nice folks, in my limited experience), but it's obviously not mandatory.

Our design sucked.

We submitted to eHub first. Then Techcrunch picked us up from there.