Mining coins makes sense as a byproduct of a productive activity of a DAC, say providing encrypted wireless mesh networking bandwidth, or providing encrypted network storage space in a Tahoe-LAFS public cloud, but otherwise seems to be a senseless waste of resources. The mining aspect of Bitcoin didn't really make sense to me when I first learned about it (when it was at .10 USD), which kept me from being an early adopter at the time.
NXT has a proof of stake in development, but Mastercoin-Exodus and Bitshares have a much more professional organization as projects.
I've been through 4 different methods of coin distribution: Giveaway with huge amount held in reserve by originators- Ripple; Purchase during public offering with deadline, no cap limit - Mastercoin; Mining - Protoshares; and Public Offering with no deadline or capitalization limit posted - NXT. Of the 4, Mastercoin, with the simple purchase of shares with a set deadline and schedule of early adopter bonuses has been by far the best.
From this experience, I would favor methods including awarding bitshares to developers for work, IPOs with set deadlines or capitalization limits and bonuses for early participants, and additional creation and payment of bitshares such as providing useful computational work related to the purpose of the DAC, provision of storage space, or supplying network bandwidth. Dividends from the DAC may awarded according to Proof of Stake or maybe it would be preferable to just let the value of the shares appreciate to avoid creating a tax liability.