Gear looks good, properly enchanted and gemmed. You could benefit from some more emblem farming, but you're doing great with what you currently have. I dislike the Onyxia polearms for DK's, but Blood tends to put out huge threat anyways so a fast weapon is not really a problem. (the agility and huge stamina are nice even if the weapon is fast)
Spec looks OK, personally I prefer speccing into Rune Tap/Imp Rune Tap as a 20% heal every 30 seconds is massively useful for raiding, but I suppose that's personal preference. I'd suggest speccing into it, trying it out in a few raids, trying to work it into your rotation (time it right after a big hit like one of Gormok's Impales or something) and seeing how you like it.