I just received a copy of the October 21, 2005 AeroSpace Briefing that
contains an infobit that I'd gotten via word of mouth some time before
the launch but didn't have a reference for:

[The] launch -- carrying what Lt. Gen. Mike Hamel, commander of Space
and Missile Systems Center, called the most important military
payload in 30 years...

That, along with the apparently incorrect report that the shroud had a
unique configuration, fueled the speculation that the launch might be
something significantly new, maybe an 8X. The first KH-11, on which
subsequent optical/IR spysats are believed to be based, was launched in
December 1976, close enough to 30 years before October 2005 for Usenet
purposes.

However, unless Big Black has done something tricky (not impossible by
any means), the last T4B mission seems to have been pretty routine and
Gen. Hamel's statement to have been somewhat hyperbolic.