Interesting. I was under the impression that you had to be hurt to holler, so to speak. Suits brought to question the eligibility of one Barrack Obama for office of President were routinely dismissed, not because of the time that had passed, but on issues of "standing"--in short, the plaintiffs could show no injury, thus had no standing to pursue the matter.
I was under the impression that an injured Party had up to two years to sue for damages, and in this case, the law being passed, and the changes unconstitutionally made did not cause injury for roughly a year. Once injury could be claimed (a violation of one man/one vote equal protection), the suit proceeded quickly and well within the two year period usually limiting suits for damages, and also within two years of the law being passed, meeting standing and time frame.
Considering it has been less than a month since that damage was incurred, and less than two years since the changes were (unconstitutionally) made, the premise on which the PA Supreme Court has dismissed the case (with prejudice, no less) is flawed.
The injury at issue as a result of a prima facie unconstitutional law is less than 30 days old, and regardless of age, the constitutionality of the law is the issue, and it would remain unconstitutional (along with any actions taken under it which superseded the constitutional constraints) no matter how much time had passed.