vaporware

from Jargon File (4.4.4, 14 Aug 2003)

vaporware
 /vay'pr.weir/, n.

   Products announced far in advance of any release (which may or may not
   actually take place).

from The Free On-line Dictionary of Computing (8 July 2008)

vaporware

   <jargon> /vay'pr-weir/ (UK "vapourware") Products announced
   far in advance of any release (which may or may not actually
   take place).  The term came from {Atari} users and was later
   applied by {Infoworld} to {Microsoft}'s continuous lying about
   {Microsoft Windows}.

   See also {brochureware}.

   [{Jargon File}]

   (2004-11-16)