HDMI Org, industry group, watching the specifications for HDMI-interface, believes illegal the cables, which are not HDMI-equipped forks on both ends.

In other words, a cable with a Mini DisplayPort connector on one end and HDMI on the other does not fall within the scope of HDMI-standard, under which the appropriate cables must have a HDMI-plugs on both sides of the wire. All deviate from the specifications HDMI-cables violate licensing regulations, so they can not sell. As a result, many manufacturers will be forced, if the group will initiate proceedings to withdraw their products from the market.
However, it is currently allowed those adapters that are being connected to the Mini DisplayPort, HDMI-carry plug cable with HDMI-plug. Still, the industry needs in the wires without any intermediate adapters, especially through initiatives gaining popularity Apple Mini DisplayPort.
via