There was only one change of note to Shadow in the patch Blizzard is releasing right now:
Mind Blast was buffed 25% from where it was in the last build. Another way of interpreting this is that Mind Blast was buffed 6.3% from where it was before the nerf in this last build occurred. This should increase the viability of Divine Insight as a talent choice, which will in turn increase the value of Mastery if you have Divine Insight selected.
One other note: most other DPS specs for other classes also saw significant buffs. I’m not concerned that we’re going to be left out in the cold (yet), since this is 2 patches in 3 days for Beta, and with 12 days to go until 5.0.4 is released I’m sure they’re pushing new builds as soon as a decent number of changes are ready, not all changes for all classes.
It is also because of this that I’m not going to do another DPS change analysis until some larger/more sweeping changes occur.