Krupski v. Costa Crociere: A Cert-Worthy Slip & Fall?

Procedure geeks were all a-twitter (again) when the Supreme Court released it's recent Krupski opinion.  And who can blame them?  The Supreme Court construed FRCP 15(c)(1)(C) on when correcting the misnomer of a party will relate back to the filing of an original complaint.

Essentially Krupski sued the marketing affiliate (Costa Cruise) when it was clear she had intended to sue the affiliate that actually operated the boat that tripped her (Costa Crociere).  By the time she got it all sorted out, limitations had run.  The Supreme Court saved her.

Eccitante!  No?

Kevin Russell of the SCOTUS Blog wrote a good summary and I won't repeat it.  But I was wondering about something else. 

I was wondering how a case that is essentially a slip and fall on a cruise ship made it to the Supreme Court of the United States.  I wish I could peer inside the black box of the Supreme Court "cert. pool" to know what made this case rise above other worthy cases that the Court rejected, if only for lack of time.

Justice Sotomayor's opinion says the court "granted certiorari to resolve tension among the Circuits over the breadth of Rule 15(c)(1)(C)(ii) . . . ."  She sets out a footnote of cases far less profound than a magnificent, circuit split.  Then she explicitly disavows any warranty of the extent to which they conflict, saying "We express no view on whether these decisions may be reconciled with each other in light of their specific facts and the interpretation of Rule 15(c)(1)(C)(ii) we adopt today."

So . . . "tension?"  That's enough?  Or is this different because it is a rule of procedure?  Absolute uniformity is more important with procedure and tension will suffice?  You SCOTUS wonks out there who have any thoughts feel free to weigh in.  I'm genuinely curious if this fits in any pattern or is just an outlier that the court reached out to grab.