I have been able to get some pretty reliable information from within the City of Plano's municipal offices as to when the filming will take place for Zack Snyder's Man of Steel.
I have it on good authority (via email) that: "we have a street closure schedule, so we are assuming that is filming time. Main St. will be closed August 6 and August 22-29. Sorry that is all of the info I have right now."-6/27/2011
Presumably this will be when Plano becomes Smallville for a short period of time. This also coincides with the previous reports and photos (courtesy of Jake Rapp) of temporary set structures being erected, because they are all on Main Street, downtown. My source on the inside will remain anonymous so that perhaps further updates can be obtained. We have opened up a pretty good dialogue so far. It's amazing what a little polite emailing can do!
So, I think we can officially get excited, folks. With filming set to commence in six short weeks, my only hope is that we get to see Henry in the new Superman Suit soon.