From http://www.nationmultimedia.com/deta...ional/30323322

"Following that request, Prime Minister Prayut Chan-o-cha in July instructed the Immigration Bureau to decide whether to cancel the requirement for visitors to use the TM6 form as part of measures to improve immigration procedures at airports and reduce waiting times. Prayut then signed an order on August 4 to issue a ministerial regulation to cancel the existing form and replace it with a new one."

It's essentially the same form, just smaller print and less space in which to write. Begins 1 October.