Level 80 Deathknight soloing Icecrown citadel 25
That was done in patch 5.0.4 - 5.0.5. I did some worldfirst solos here: Lady deathwhisper (25N), Blood Queen (25HC), Lich King (25N).

Armory http://eu.battle.net/wow/en/character/silvermoon/Dr�latius/advanced

I did not add any effects, just simple title before each boss + video speed-up. If you want to watch the movie in better quality please watch from Youtube
http://www.warcraftmovies.com/movieview.php?id=222775&stream=1
or on my Youtube channel
http://www.youtube.com/watch?v=uO5D-prXgoA

Consumables used: Runescroll + drums, of course. Usually using crit food and crit elixir for dps and death siphon, resist elixir to survive magic damage or sta flask to get max stamina to prevent oneshots. Also i used Adventurer's journal to get some rare buffs like +15% damage to undeads or a chance to be healed for 4-6%.

Tracklist:

Bart Klepka - Doomed on Dune
EagleGuard - Release
Hollywood Undead - Undead
F4LL0UT - Rise of the Vampire Lord
Mazedude, Ailsean - The End of Hell
Ashley Carr - Doom 2 MAP18 Remix
Larsec - Darkness Dawning
Scott Peeples - Contamination
Jovette Rivera - The Countdown
Vedrim - No King Rules Forever

About the stats- at this moment there is a ballance between haste, crit and mastery and knowing what you need for certain fight will boost dps, healing and survivability. Mastery gives blood shield, each time you deathstrike it stacks as a melee absorb shield, more damage you receive- more deathstrike will heal and higher bloodshield you will have. Haste is another key for DK soloing - it affects autoattack speed, but not only; it affects the rune regeneration time, so you can use deathstrike and other attacks more often, and with Scent of blood talent you can get increased DS heals by doing autoattacks, more haste - lower weapon speed; it boosts both dps and healing. Crit is the 3rd key- first its a dps stat, as a blood DK dps you need approximately equal values of crit and haste for maximum dps, but there is another thing- i have Death siphon talent that scales extremely effective with Attack power, its an attack that also heals you for the same value as the damage inflicted, so it can do a crit damage, giving you a doubled heal and that heal can crit too- the healing from it is linear dependence from attack power and quadratic dependence from your crit.

More info about stats and bosses is here: http://www.mmo-champion.com/threads/1214536-80-DK-solo-Icecrown-Citadel-25-7-12-HC-3-12-Normal

PS: Some info about wipes: Marrowgar ~10, LDW 36 (!!), Saurfang 0, Bloodprince ~ 6, Lanathel 3, Rotface 2, Festergut 18, Professor 22, Sindragosa 4, Lich King ~20.