Holding that, in the absence of a controlling decision from a state's highest court on an issue of state law, a federal court sitting in diversity must predict how the court would rule by considering the relevant decisions of the state's appellate courts
Holding that the district court may have been "correct" in not finding a "joint employment" relationship "if one considers only the name of the payor appearing on [plaintiff]'s pay stubs. But [plaintiff] alleges more. The Amended Complaint states that an employee of [defendant] conducted Thompson's training . . . indicating that [defendant] had at least some authority to 'promulgate work rules and assignments'"
Providing that registration as a foreign corporation in the state "constitute a sufficient basis of jurisdiction to enable the tribunals of this Commonwealth to exercise general personal jurisdiction over [it]"