We will likely have the dates for all the venues and the group stage schedule before Thursday(likely Wednesday) because that is the day Ticketmaster has as a sale date for some of the non-Rose Bowl tickets. They have already revealed that: Miami (Sun Life Stadium) will host group stage games on Friday July 12th. We can safely say (irrespective of a rest day on July 10th) that Miami will NOT host Mexico's group. Dallas (Cowboys Stadium in Arlington) will host the semi-final on Wednesday July 24th. Credible rumours say that Chicago (Soldier Field ) will host the final on Sunday July 28th (especially now that we know it won't be at the Rose Bowl or in Dallas).
So more than likely: Pasadena, Denver, Atlanta-Mexico's Group. Hartford, Salt Lake, Portland-USA's Group New Jersey, Miami, Houston-Miscellaneous Group (High Possibility of Honduras again.) Quarters: Seattle, Baltimore Semis: Dallas Final: Chicago
Have you heard announcements about ticket sales or did you just check Ticketmaster? Ticketmaster lists the July 7 game as going on sale March 13 at 10AM. The 7/12 game in Miami is going pre-sale on 3/14. I'd hope to hear about these a little more in advance, but I haven't seen anything from US Soccer.
I just checked Ticketmaster; why would they start selling tickets if none of the teams were known? CONCACAF said mid-March, so it seems likely that venues and groups will be announced before tickets go on sale. For the July 7th games, tickets are already on sale because 1 team is known (Mexico). The link you provided is for "suite tickets". The normal ones are already selling.
http://www.chicago-fire.com/news/2013/03/fire-head-kansas-city-mls-rivalry-week-clash Told yall it would be "likely wednesday".