You're doing fine as far as I can tell. A bit heavy on mp5 and light on int, perhaps, but with so much Naxx gear, you can't really avoid the mp5, it was itemized by Blizzard employees with an mp5 fetish...
The only real upgrade path I can see is to swap in the Argent Crusade helmet and ring, but you're only honored - and you'll get the tier helm soon enough, I'd expect. And
Renewal of Life might be a worthy place to sink a few Valor emblems.
Depending on how hard your guild is finding the content you're at, and especially if you're going for achievements, I'd consider throwing away some of your weaker socket bonuses and gemming pure +int, 17k unbuffed is a bit light.
Also consider replacing the Egg, at least for some fights, with
Darkmoon Card: Greatness. I happen to know from firsthand experience that if you shop carefully for the individual cards, you can get it for 7k on your server.
The only other thing I can think of is to save some DKP for a Holy Paladin weapon instead of whatever it is you're carrying. It's not worth going back to Nexus for the War Mace at your gear level, but there are 4 461sp and 2 520sp weapons in Naxx, all of which will do you well.
Edited, Feb 17th 2009 3:32pm by ElMuneco