Just to give everyone a heads-up, Ticketmaster has posted the on-sale date for tickets to the Chelsea v Sounders game, which will be taking place in Seattle on Wed July 18. Tickets go on sale on June 4 at 10 AM (PDT).
No word yet on tickets for the game in Baltimore / Washington DC, or the game in Philadelphia. And still no official confirmation (that I've seen) for the alleged game at Yankee Stadium. I'll pass along any info as I come across it.