I'm guessing by now that everyone has noticed that the Zoning Board of Adjustment rejected the zoning variance that would allow Unisys to construct its logo two-thirds of the way up Two Liberty Place. See Inquirer coverage. Unisys had already signed its lease that will move 225 of its employees into Two Liberty from Blue Bell before this decision was made, and has said publicly that this decision is not a deal-breaker.
There have been some interesting looks at sky-writing since this controversy bubbled to the surface earlier in the year. Most recently, there's Inga Saffron's column outlining Philadelphia's tradition of letting major companies advertise with large signs atop their skyscrapers. Brad Maule broke the Unisys story on Philly Skyline: click and scroll to see his April 8th entry, his April 15th entry and his June 6 entry.
Perhaps these conversations will be a starting point to talking about the presence of billboards (legal and illegal) in the city. SCRUB has been at the forefront of this dialogue, and it would be interesting to see how conversations about sky-writing and logos could carry over into this equally contentious area. Billboards take many forms in Philadelphia, from illegal liquor ads atop abandoned buildings to promotional signs for luxury Center City condos. Dranoff Properties' Locust on the Park is a prime example of the latter: they replaced their old sign with a new subtler one earlier this summer.