It might not really look cube-like, but the KanexPro CubeUp does quite a bit to convert 2D content into 3D for playback on 3D-enabled screens.
The CubeUp is a 4x1 switcher, handling up to 4 HDMI sources-- with the addition of real-time 2D-to-3D hardware conversion. Users can also adjust 3D viewing parameters, including depth and scaling, using the included remote.
It can also upscale source resolution from 480p to 1080p, improving both frame-rate and resolution.
In addition, it also has a pass-through mode, passing through HDMI output without any processing if required, and confirms to High Speed HDMI specifications providing Deep Colour, lossless audio and all HDCP requirements.