Definitions for vaporwareˈveɪ pərˌwɛər
Random House Webster's College Dictionary
a product, esp. computer software, that is announced and promoted while it is still in development and that may never come to market.
Origin of vaporware:
An advertised product, often computer software, whose launch has not happened yet and might or might not ever happen.
The New Hacker's Dictionary
Products announced far in advance of any release (which may or may not actually take place).