Well no one has seen him since May 6. The following lists the key Thai holidays for 2014.
http://en.wikipedia.org/wiki/Public_holidays_in_Thailand
12 Aug will be a key date since it is the birthday of the Queen. It will be rather odd if both king and crown prince are "missing".
The really key deadline after that will be 5 Dec, the birthday of the king. If they plan to install the princess as regent, they will have to do it by then.
We are therefore looking at a timeline of 3 to 6 months.
Incidentally the crown prince is in Hampshire with a delegation of 30. Unlike his normal pattern of being with one of his many mistresses, he is actually with his wife. His 9-year old son is not present. That video of the crown prince and his topless G-string wife has been widely circulated in Europe as the governments sympathetic to hosting Thaksin's government-in-exile are mainly based in Europe.
On the queen, the South hate her because of her previous arming of the militias in the South to try and repress the Muslims. She has become equally hated in the North and North East for her role in the 2006 coup that removed Thaksin. Marie Antoinette would probably be the description that best fits her.