This report seems to have the most updated information:
The Thai army declared martial law nationwide in the early hours of Wednesday after a coup to dismiss Prime Minister Thaksin Shinawatra, a coup spokesman said in a televised address. He also ordered all soldiers to report to their barracks and banned troop movements unauthorized by the coup leaders. The army took control of Bangkok and announced it would set up a commission to reform the constitution despite Thaksin declaring a state of emergency from New York.
........All television channels relayed a written statement saying the armed forces and police were in control of Bangkok and surrounding provinces, and appealed for calm.It said the armed forces and police had set up a commission to decide on political reforms, ousting Thaksin in the midst of protracted political crisis in which he was accused of undermining democracy.
Weerasak Kohsurat, a deputy minister in a prior government, told Reuters he believed royal adviser Sumate Tantivejakul would head the reform commission and an interim government would be formed while political reforms were agreed.
The army-owned T.V. station has been "showing images of the royal family and songs linked in the past with military coups." An announcement was made saying the troops belonged to the "Council of Political Reform", a council that is/will be established by the military and police forces to institute constitutional reforms. Thaksin's declaration of a state of emergency aired on Thai T.V.s for 10 minutes - at which point the broadcast was cut off while he was still talking. That certainly doesn't bode well for the Caretaker Prime Minister.
The military has taken control of all T.V. and radio outlets in the country, and people in Thailand have also reported that news websites in Thailand have been blocked, so although the atmosphere there seems to be calm, residents haven't been able to get any information on what exactly is taking place.
Ultimately, we'll just have to wait and see what happens. Military coups aren't uncommon in Thailand, and at this point in time, it doesn't appear as thought the military is settling in for the long haul. Thaksin's rule has been rife with controversy and corruption, and one certianly couldn't accuse him of advancing or strengthening democracy in Thailand. But, military coups aren't exactly a reliable method of checks and balances. The King has been put in an interesting conundrum here as well, with the military declaring loyalty to him. Even though that's a bit redundant, as everyone in Thailand is loyal to the King, but, their point is still made. What are the King's options here? He has a fine line to walk between not overtly choosing sides and subverting the democratic process. And yet, the coup has been staged, and if the military calls on the Royal Advisor to lead this new council, the King has little recourse not to participate in the process. Certianly, the whole thing is just a mess. Thaksin has little claim to legitimate democratic rule, but, a military coup does little towards strengthening the democratic institutions or the respect for such institutions which is necessary to stabilize Thailand's democracy for the long haul. King Bhumibol may be a stabilizing force who can help diffuse this situation and restore a legitimate government in Thailand, but as many people have pointed out, he won't be around forever. What happens when the next king is not as patient or doesn't understand the gravity of his responsibility? The Thai king has immense power in influencing politics, but if Thailand is going to survive as a democracy, they'll have to establish institutions that can stand on their own, without royal intervention to keep things in check. The next step in this coup crisis should be that which will take Thailand towards a stronger democracy where the power of accountability rests with the people and not the military or the monarchy.
Links:
Coup sparks Thailand emergency
Thai Military Launches Coup Against Prime Minister