One planned new province which occasionally shows up in Thai news is the one planned to be formed from the northwestern part of Khon Kaen, with the district Phu Wiang as the new capital district. By some random googleing I have something new to me about this plan. According to a news posting named ขอนแก่นเปลี่ยนคำขวัญจังหวัดใหม่ หลังจากได้รับพระราชทานนาม “สิรินธรเน่” at the region division of the Public Relations Department, it is now suggested to name the new province after HRH Princess Sirindhorn. Sadly that page does not give the date of its writing, and also does not say anything about when this new province will come into existence. However a google search for "จังหวัดสิรินธรเน่" gives zero results, so either this report is very recent or it did not get the royal endorsement to use this name.
The new province is set to consist of the seven districts Nong Ruea, Chum Phae, Si Chomphu, Phu Pha Man, Phu Wiang, Nong Na Kham and Wiang Kao, as shown in the map of Khon Kaen Province above. However I have no idea what is the current status of this proposal, all the websites I can find by searching for "จังหวัดภูเวียง" (or "จังหวัดชุมแพ", Chum Phae, which is another name proposed for this province) seem to be older than 2006. Either the plan has been shelved, or it is quietly continuing now - I'd love to know the current status.