There is a moco bulletin out on this. M-1304 - big twin neutral rattle.
My 09 had it and my 11 has it even worse!
And, yes, they say it is normal.
The bulletin says - When a motorcycle is at normal operating temperature and in neutral, a rattling sound may be heard on the right side coming from the area of the transmission side cover. This sound is normal and is referred to as neutral rattle. To verify the sound is neutral rattle, pull in the clutch lever and hold it for 10 to 15 seconds. If the sound stops, it is neutral rattle. Neutral rattle is caused by the necessary backlash within the first gear pair.
Theres more but too much for me to type
Again bulletin number is M-1304 and was issued on 8-31-2011
Gary D.