The Employee Free Choice Act, HR 800 and S 1041, is moving through Congress. The three main points of it are:
1. It strengthens financial penalties for companies that illegally coerce or intimidate employees in an effort to prevent them from forming a union;
2. It brings in a neutral third party to settle a contract when a company and a newly certified union cannot agree on a contract after 90 days;
3. It establishes majority sign-up, meaning that if a majority of employees sign union authorization cards validated by the National Labor Relations Board, the company must recognize the union.
For more info see the AFL/CIO site regarding the legislation. It looks like all of PA's Democratic representatives (plus Republican Tim Murphy) supported it. Sen. Casey has signed on as a co-sponsor. Sen. Specter has not. (h/t Mike in Chicago)
Full disclosure: I am a union member and have in the past and will be again this year, holding office in our local chapter.