As Brandon posted, OCS and Speech Server are available for anyone and everyone to beta test. Here are the links you might need:
Beta Forums:http://forums.microsoft.com/ocs2007publicbeta/default.aspx?siteid=57
Speech Server (2007):http://www.microsoft.com/downloads/details.aspx?familyid=4F4D3AA4-8223-406C-B74F-DB2DE928D8B2&displaylang=en
OCS 2007 Beta:http://www.microsoft.com/downloads/details.aspx?FamilyID=f7d34df9-29cf-4bfc-824f-7a382ce8ba8b&DisplayLang=en
As Brandon and Michael have pointed out the beta for Office Communications Server 2007 Speech Server