During their live chat with fans on the 17th, the Wonder Girls announced that they plan to perform in more locations around the US and will have several stops in Canada as well.

Hawaii (2 shows), Vancouver, Seattle, San Jose, Las Vegas, Denver, Chicago, Detroit, Toronto, Montreal, Boston, Connecticut, New Jersey, Philadelphia , Virginia, Tampa, Orlando, Miami.

The exact dates and venues were not announced, but it seems like the list they were reading had the tour locations in a correct order.

These new locations will be added to their tour which already includes?
June 04 : Washington DC / Warner Theater (VIP sold out)
June 05 : Atlanta / Tabernacle
June 06 : New York / Hammerstein (VIP sold out)
June 08 : Chicago / House of Blues
June 09 : Houston / House of Blues (VIP sold out)
June 10 : Dallas / House of Blues (VIP sold out)
June 11 : Los Angeles / Palladium
June 12 : Anaheim, CA / House of Blues
June 13 : San Francisco / Fillmore (General and VIP tickets sold out!)

Tickets can be bought at http://www.livenation.com/artist/wonder-girls-tickets

The Wonder Girls also said that 2PM will open for these first 9 shows.
Edit: I think I heard them wrong @ 4:08 into the video. "2PM will be our opening act, and also 2AM, but for the 9th confirmed city, only 2pm will be joining our tour". As someone posted in the comments "Yenny corrected herself and said as of now only 2PM is confirmed".

*The "sold out" status of tickets was found out by trying to purchase those particular tickets from Livenation.

YAY!! Miami!!