Smerconish will provide talk listeners, another option that isn't right wing GOP talking points during the 12n-3pm time slot other than NPR programming on WHYY-FM. As mentioned by someone else, Smerconish's show has a moderate slant to it, and as Philly is a blue town politically, WPHT should do just fine in the city of Brotherly Love. Rush isn't changing his show, so there is nothing new there, so will his move to FM really attract that many new listeners? Maybe some who can't get Philly's WPHT so they've been trying to get NYC's WABC, Wilmington's WILM, or even Harrisburg's WHP would probably go to 106.9. So yes 106.9 could take some listeners from the rim shot stations that surround Philly. The rest of Philly's ditto heads will simply switch from 1210 to 106.9. So with a city/metro area full of moderate to left leaning folks who aren't interested in a thing elRushbo has to say could help WPHT to come out the winner in that 12n-3pm time slot in Philly with Smerconish. Also as Smerconish has a moderate show, it might be an easier for WPHT to sell the local avails than with Limbaugh.
WPHT could also take a goodly part of the Wilmington talker audience away from its two news talkers (WDEL and WILM) as the major population block of the Wilmington market is primarily blue also. 1210 throws a solid signal into the Wilmington metro area. Both news talkers air conservative talk from noon-3pm. So a moderate leaning talk show like Smerconish could go well against Limbaugh on WILM and Jensen - live and local conservative on WDEL.
I guess time will tell.