@phlmaestro:  Great news about Shake Shack.  I’ve heard about them and I’ve even thought about a roadfood roadtrip to NYC.  In addition, to custard, supposedly great burgers and hot dogs.  In NYC they’ve also got beer and wine but we’ll see what happens when they go up against PA liquor laws.
@Leechef:  300 miles to Butler County for frozen custard is a stretch, even for me.  But if I’m ever in the area, I’ll make a point to check it out.  Maybe in connection with a pilgrimage to the first Handels.  20 flavors of custard is exceptional: Usually it’s only vanilla, chocolate and one flavor of the day. 
 
I recently tried Zwahlen’s in Oaks, PA (mentioned above).  It was scooped custard (not soft serve custard).  Rich and heavy with a nice vanilla taste.  The flavor that day was butter brickle but I can’t stop thinking about black raspberry custard.  [:)]
 
UPDATE: Square Burger is now open for the season in Franklin Square (Center City), similar in concept to Shake Shack, with burgers, dogs and – yes – custard (instead of ice cream, as in prior years).
 
Shake Shack is scheduled to open at 20th and Samson, near Rittenhouse Square, sometime this summer (possibly June). 
www.uwishunu.com/2012/03/shake-shack-construction-officially-underway-near-rittenhouse-square-pop-up-corner-park-unveiled-on-site-with-a-living-green-wall-just-in-time-for-spring/