Err, These changes have already been mentioned/were on the PTR. The mastery change was suppose to be a buff, but they decided not to buff our mastery. So there's really no nerfs here.
The change I thought you were talking about was the sudden death change. Which can be seen as a buff since you can control when SD procs(OP will now proc SD instead of auto attacks).
Anyways, arms will end up with an overall damage buff this patch. As it is behind in pve. So this is kind of a pointless QQ thread.
A good change in those notes is that wild strikes will also increase DbtS duration with the glyph, though.
Edited by Deonto, 23 January 2013 - 11:22 PM.