The season finale of House was shot with a Canon 5D Mk II. The 5D is Canon’s “prosumer” DSLR camera — in other words, it’s a still camera that also takes HD video, not a purpose-built HD video camera.
At $2,500, it’s not cheap, but it’s also not so expensive that normal (but devoted) photographers can’t have one — it’s laptop territory, not used-car territory.