DSDR KB:

There are 3 releases of the ACS data. The release schedule will follow this pattern in subsequent years as well.

The first release had the income/poverty data and is summary data only.

The second release will include all the rest of the items for the summary data and will also include microdata (PUMS). This will be September 23rd.

The final release will be 3-year data (2005-2007) for units of geography with populations of 20,000+. This will occur "in December."

Here's a link to the Census Bureau's press release:

http://www.census.gov/Press-Release/www/releases/archives/americancommunitysurvey_acs/012462.html