From Catherine Lucey at the Daily News, here is the decision from Commonwealth Court, upholding the city's right to enact its own campaign finance laws.
I know... It's 50 pages long. I'll see if I can pull out the salient points. Check back in a few.
(edited to add)
Ok... I read through and got to the part where the court actually makes its decision (starting on page 27):
With the foregoing principles in mind and having examined powers conferred upon Philadelphia, as a home rule municipality, by constitutional and statutory provisions and the Home Rule Charter, the Court agrees with Nutter and the City that the Ordinance is not preempted by state law. A review of the Election Code demonstrates clearly that it contains no "express preemptive mandate." The Supreme Court has on numerous occasions explained that the Election Code is a lengthy and comprehensive piece of legislation that governs the "holding" of elections in Pennsylvania.
(snip)
With regard to campaign contributions and expenses, the Election Code regulates, inter alia, the organization of political committees; the registration of political committees when they receive more than $250 in contributions; requirements for candidate and political committee reports when they receive $250 or more in contributions or expend $250 or more; filing of annual reports; disbursement of residual funds when a candidate or political committee ceases activity; and restrictions on contributions from banks, corporations or agents of donors or the disbursement of contributions made by anonymous sources (payable to the State Treasurer). Cash contributions that exceed $100 are prohibited.
(snip)
The Election Code contains no language to show express or implied legislative intent to legislate with respect to limits on campaign contributions to candidates for local elective office.
(snip)
Because there is no indication of legislative intent to preempt the field of campaign finance as it relates to campaign contribution limits for local elective office, the Court concludes that the Ordinance is not preempted by state statute. Notably, all references in the Election Code to the dollar amount of campaign contributions received or the amount of expenses incurred relate solely to legislative establishment of threshold limits for public disclosure purposes.