We had decided to end IE6 support sometime ago, but IE7 is proving a real obstacle to progress too and has subsequently also been added to the unsupported list.
IE10 is now available (Win 8, and in preview on Windows 7), which places IE7 as three generation old.
So, we can invest time in supporting a rapidly dying browser , or force an upgrade on those still using it.
We understand some may have no choice, and if that is the case, please discuss here. We may be able to provide a solution. But the only real solution is to move to IE8 or above.