Your spec looks good. Your gear, on the other hand, has way too much hit. Try getting the helm from Onyxia, going 4x T9 + that is what most Shadow Priests are going for. For a really detailed list of what gear trumps what, take a look at this list: http://www.shadowpriest.com/viewtopic.php?f=62&t=22720
Just to start you off, your Intellect trinket is pretty awful for Shadow Priests. Very much of your hit gear can also be replaced with pieces with more pure dps stats, as we inherently get a lot of hit from our T9.
Lastly, are you multi dotting on the fights where it's useful?
Im working on a new neck and trinket, waiting for the neck from Twins and Reign of the dead, also for the head i havnt been lucky enough to get the one from Ony yet.
as for multidoting im trying to do it as often as possible thanks for the replys