Here's another thought:
I'm sure not the first to think about this, but for cover collectors it seems we can order from SFS a very nice combination of patriotic-themed stamps that will total the new first class 49-cent rate that will be especialy nice for pictorial cancels and the like:

It seems to me a cancellation would show up so much better on a cover with this stamp combination than the upcoming Star Spangled Banner "Forever" stamp that has a black background and will not lend itself well to special postmarks.