OK, a little reality check. I am not privet to the agreement between MLB and WGN so I can't comment as to the veracity of the press release, however I do have a bit of first hand information about the WGN Cubs HD telecast of last year and can also report that two more telecasts are planned for this season.
While HDNet may have provided some of the physical facilities used in last years broadcast, most of the work was done by WGN employees, the same freelancers that they use to crew their SD telecasts, and engineers from Trio Video who provides the broadcast facilities for the SD telecasts.
I personally saw engineers from WGN cabling Wrigley for the telecast and I know cameramen, audio engineers and video engineers who participated in the broadcast. So to say the all GN did was piggyback on HDNet's production is not true.
Another point to take into account is that there aren't a ton of HD capable TV production trucks out there. There are only a handful in the entire country. Building one of these trucks costs millions of dollars and most truck vendors don't see the demand out there that would justify the investment. While this leads to one of those vicious circle situations where there's not enough HD out there to justify the cost of a truck and you can't do more HD because there aren't enough facilities, etc., please remember that the truck companies are owned by people and staffed by people who have to make a living and put food on the table just like you, and the industry has been squeezing them pretty good the last few years as broadcaster cut costs wherever they can to pay for the exorbitant fees they've promised the major sports leagues.
I, too, would like to see more HD programming, especially sports, but at this point in time the economics of the business dictates that the growth will be slow for a while.