Okay, lets look at this historically.
SME 5.0 released 9/19/01
SME 5.1 released 2/6/02
SME 5.5 released 7/3/02
If you extrapolate this out it puts the release of SME 5.6 in early December.
I'll guess 12/4/02
Of course I won't be making any business decisions based on this!!!!