First off, the bill does exactly what it sounds like: it prohibits texting. That doesn't include fiddling with your radio, dialing a phone number to make a call, or using your GPS.
If you get stopped, the police aren't permitted to take your phone under this statute, although they are not prohibited from doing so for some other appropriate purpose. The ticket is for $50 and carries no points for non-commercial drivers, nor will it appear on your driving record. There are no enhanced penalties for second or subsequent offenses.
One of the most interesting facets of this statute is that it expressly " supersedes and preempts all ordinances of any municipality with regard to the use of an interactive wireless communications device by the driver of a motor vehicle." That strongly suggests that the Philadelphia ban on voice calls while driving is no longer good law.
Another implication of the statute is that it gives rise to greater civil liability for drivers by exposing them to suit under a theory of negligence per se. Consider, for instance, the relative liability of a driver who stops suddenly while texting, and is then struck from behind. Under prior Pennsylvania law, fault for the rear-end accident is (nearly) always placed on the rear vehicle, on the theory that all drivers should be prepared to stop when necessary. With the aid of the new texting statute, the rear vehicle could argue that the other driver was negligent per se by breaking the new texting law.
The theory hasn't been tested yet—after all, the law is just a few days old—but it'd be worth requesting texting records during discovery in auto-accident cases all the same.