Adobe
Adobe maintains a list of native DNG compatible cameras here (for the purposes of seeing what's compatible with Adobe Camera Raw)
The list consists mainly of Casio, Leica, Pentax, Ricoh and several Samsung cameras. It might be worth checking the page however as more cameras are added and of course confirming with the manufacturer before making a decision.
neocamera
For a list of current DNG supporting cameras, it is any easy search on Neocamera, just select the DNG check box. Here are the results.
