you've been assigned a Visa #

From http://uscis.gov/graphics/howdoi/immvisa.htm

If you want to become an immigrant, you must go through a three-step process. First, the USCIS must approve an immigrant petition for you, which is usually filed by an employer or a relative for you. Second, a visa number, through the State Department must be immediately available to you, even if you are already in the United States. If you receive an immigrant visa number, it means that an immigrant visa has been assigned to you. Third, if you are already in the United States, you may apply to adjust to permanent resident status after a visa number becomes available for you. (If you are outside the United States when an immigrant visa number becomes available for you, you must then go to your local U.S. consulate to complete your processing.)

这就是说485被接受后，你已获得一个Immigrant Visa Number。

另外，请以美国务院Visa Bulletin消息为准。这则新闻也就不新了，请看

http://travel.state.gov/visa/frvi/bulletin/bulletin_2539.html