Thank you so much for reading - I wrote that article before we visited at Christmas time. If you are interested I invite you to take a look at these two posts:
http://communicatingacrossboundariesblog.com/2011/12/29/tahrir-square-walls-and-graffiti/ and
http://communicatingacrossboundariesblog.com/2011/12/26/cairo-christmas-a-weary-world-rejoices/