From the NY Times, I am having a hard time reconciling these statements from the same article:
The law provides a partial exemption for certain health plans in existence on March 23, when Mr. Obama signed the legislation. Under this provision, known as a grandfather clause, plans can lose the exemption if they make significant changes in deductibles, co-payments or benefits.
About half of employer-sponsored health plans will see such changes by the end of 2013, the administration says in an economic analysis of the rules.
About 133 million Americans are in group health plans from employers with 100 or more employees, the administration said, and most "will not see major changes to their coverage as a result of this regulation."
My translation: Yes, you will lose your current health plan despite Obama's promises, but he doesn't want you to realize this until 2013, conveniently just after the next presidential election.