The ultimate outcome is a crucial one to the now-struggling corporate reform effort, according to Nell Minow, editor of The Corporate Library, an independent research firm specializing in corporate governance issues.

Proxy access is the most important of all the reforms that have been passed or proposed in recent years, she said. That's because it was the only reform that has the potential truly to empower shareholders by giving them the chance to take on entrenched boards and imperial CEOs.

No wonder then that business leaders have been so adamant in their opposition.

Led by the Business Roundtable and the U.S. Chamber of Commerce, corporate America has fought bitterly against the proxy rule, part of a broader effort to challenge the Sarbanes-Oxley law and other post-Enron reforms. The efforts have seemed to gain strength in recent months: SEC members are deadlocked over the proxy access rule, with Chairman William Donaldson having withdrawn his earlier support.

Should reformers lose the fight over proxy access, the reform movement may end without fundamentally altering the balance of power between investors and corporate managers.

This Firm Is Your Firm

To be sure, shareholders do have some say in corporate affairs. Mergers, management option plan proposals and shareholder recommendations all require investor votes. But when it comes to determining the composition of corporate boards, shareholders have little power.

In a typical election, board candidates are nominated by sitting board members and generally face no competition. Further, shareholders usually don't have the option to vote against director candidates, only to vote for them -- or abstain.