Maybe this is all you need!
Four XLR inputs, 4 HDMI inputs, USB out... onboard Video switcher with chromakey...! If this has been available when i was first looking I may have gone this route. For about 2 grand it seems like a great fit for podcasters doing video. Especially if you are mostly doing it solo.
http://imagizer.imageshack.us/v2/640...0/707/qm8l.jpg
http://imagizer.imageshack.us/v2/800...0/542/j788.jpg
http://imagizer.imageshack.us/v2/800...0/850/vdvk.jpg
http://www.rolandsystemsgroup.com/products/100137