Justiciability of Political Gerrymandering after Vieth

SCOTUSBlog has a post up on the court's vacation of a federal court's upholding Tom DeLay's redistricting plan in Jackson v. Perry. Election Law Blog has more here. Jonathan Adler of The National Review, who favors the Texas redistricting plan, says that this is much ado about nothing, but I'm not so sure. By granting review and summarily reversing, it seems to me that the Court is implying that 1) There are real standards a redistricting plan must clear in a challenge under a theory of political gerrymandering, and 2) that the case in controversy here has a legitimate shot at not reaching those standards.

Hopefully, someone with a better understanding of either election law or the Supreme Court's practice of vacating for reconsideration may shed better light on what is going on than I can. Please comment.