Hot off the press
HDMI 4x2 Matrix Switch
Gefen makes a
4x4 HDMI Matrix Switch but it's over $1500
There is ->
this <- one too. Not sure how much $$$ though.
The other way to do it would be to have a 3 way splitter for each source (1 in 3 out) and run one of each split source to a switch, and then the switch to the TV. The matrix switch just makes it cleaner with less wires and hassle. It might cause HDCP or HDMI handshaking issues also.