Microsoft announced at its partner conference on July 10 that it will launch Windows Server 2008, Visual Studio 2008 and SQL Server 2008 together in a single launch on February 27, 2008, in Los Angeles.
Microsoft officials have been saying for a few months now that while the company planned to release to manufacturing Windows Server 2008 (the product formerly known as "Longhorn Server") before the end of 2007, it planned to launch Windows Server 2008 officially some time in early 2008.
(According to my sources, Microsoft is planning to RTM Windows Server 2008 -- as well as Windows Vista Service Pack (SP) 1 -- in November. All Microsoft will say publicly about its Windows Server 2008 RTM schedule is it's on track to RTM "before the end of the year. It won't say anything on its plans for Vista SP1 RTM.)
Microsoft has yet to release Beta 2 of Visual Studio 2008 (code-named "Orcas"). That beta is expected some time "this summer." Microsoft officials have said they expect to release to manufacturing the final version of Visual Studio 2008 in either late 2007 or early 2008.
Microsoft recently released a private Community Technology Preview release of SQL Server 2008, code-named "Katmai." Earlier this year, Microsoft said to expect SQL Server 2008 to be released to manufacturing some time in 2008. (It's not clear whether Microsoft will release to manufacturing the final SQL Server 2008 bits before the big February launch party.)