6 Month Validity
This actually means up to 9 months if you time it right. Get the new visa 2 weeks before you leave for Thailand, then come and go as you please making sure you fly back into Thailand a day or two before your 6 months run out. That way, you get a full 60 days from that day, plus the option to extend it for another 30 days without leaving the country, giving you up to 9 Months in Total!
Example: If your 6 month visa is valid from January 1st to June 1st you can come and go as much as you like during that time for up to 60-90 days at a time, then just make sure you re-enter Thailand before May 31st, and you'll get 60 days from that day + an option to extend it for another 30 days, giving you close to 9 months in total.
Death of the Double and Triple Entry Visas:
Unfortunately, this is something no one knew about until just now, but with the introduction of the new 6 month multiple entry tourist visa we lose the option to obtain a double or triple entry tourist visa. We'll still be able to get single entry visas which are good for 60 days + a 30 day extension, but it rules out going to places like Laos to get a double entry.
How to Obtain a New 6 Month Visa:
The only downside to getting the new 6 month visa is that you have to do it from your home country, or a county where you can prove residence in.
That means for most of us already traveling in Thailand or SE Asia, we'll have to fly back home to get the new visa. The good news is, if you use my 9 month plan I mentioned above, you'll only have to do it once a year or so, and can use it as an excuse to go to weddings, or see your family that I'm sure misses you.
The cost of the new visa is around $140 USD and in my opinion is a fantastic deal for a 6 month multiple entry visa as it gives us both freedom of time and schedule. In my first book 12 Weeks in Thailand I wrote about how to live the good life on the cheap, make border runs and get by on $600 a month, but those days are over.