SQL Server 2012 is due to be released in the first quarter of 2012. It will feature three main editions.
NOTE: Bookmark this thread, as we will update it to include future information as it becomes available.
The three main editions
Enterprise, BI (Business Intelligence) and Standard. In addition there will still be Web Developer and Express versions of SQL Server 2012.
Microsoft will be eliminating Datacenter (features now part of Enterprise), Workgroup (Standard replaces it) and Standard for Small Business (Standard replaces it).