The engineers behind Templeman Automation are developing Playsurface, an affordable open-source touch table for “ordinary developers and consumers.” From their Kickstarter page:

Our development of Playsurface started by assembling the best open-source optical touch table plans available, and we intend to create a hackable, multi-use, blazingly fast touch computing platform for gaming, music, browsing, device control, and other applications. The goal is to enable cutting-edge performance at a price point that makes buying a touch table similar to many consumer home computer purchases.