Both from the lack of announcements in the Royal Gazette as well as from the numbers on the last two DOPA annual reports, the were no new administrative villages (Muban) since 2007 - except the single one just announced shortly ago. As the annual reports last came in March, it's still too early for a definitive answer, but I am now quite sure there are more Muban announcements to be published soon.
In the news report from July 2008 by the Public Relations Department titled หมู่บ้านตั้งใหม่ 9 แห่ง จังหวัดมุกดาหาร ได้รับจัดสรรเงินกองทุนหมู่บ้านงวดที่ 2 nine new villages in the provinces Mukdahan have their funding allocated already. While it does not say which date these villages get actually created, I wouldn't be surprised now to see these villages in the Royal Gazette soon, more than a year after the funding was approved.
The article only lists the districts, but not the subdistricts, which will get new villages