Whilst PS3 and PC owners will have to wait until the end of this month to pick up Dawnguard, Xbox360 owners saw the DLC release just over a week ago due to an exclusivity deal with Microsoft. But does Dawnguard's content justify a pretty hefty price tag of nearly $20, and was the initial excitement for the content short lived?
The main focus of Dawnguard is on the new questline and factions it has to offer. Players will choose to join the Dawnguard, an ancient group of vampire hunters, or the vampires of Castle Volikihar. Word to the wise, make sure you save your game before choosing who you're going to side with. If you're like me and ould never be arsed with the hassle of plowing through the various side quests that would rid your lycan blood, you'll be relieved to discover that siding with the vampires will eradicate your werewolf traits. But choose wisely; once you've made your decision you're stuck as one of the two for good.
Bethesda has taken the chance to expand the perks of being either a werewolf or a vampire, and both come respectably with new skills trees. Unlike your usual skills, which require points to level up in, levelling up as a vamp or wolf is done by the amount of blood you spill. Each kill you make whilst in vampire or werewolf form will fill an experience bar at the bottom of the skill tree, accessed during your transformation. The vampire skill tree has some pretty cool unlockables, whilst the werewolf tree focuses on buffing out your strength and extending the time you can spend as a werewolf. 
My main criticism with the DLC is because of these transformations. Whilst the idea of hovering around as a hard-as-nails vampire lord may sound fun, the reality of it is beyond frustrating. Upon either transformation, players are limited to a third-person perspective. At times, this can make controlling your character extremely difficult, resulting in a clunky feel when you find yourself in a tight spot. It's too easy to find yourself losing track of enemies during combat, as they easily disappear and reappear off screen unknowingly. The must frustrating disadvantage of all of this is finding yourself stuck in a small dungeon, or your progress prohibited due to the now gargantuan-like build of your character. There's still no way to pick up items as a werewolf or vampire lord; often resulting in backtracking through the mess of bodies you left behind as your alter-ego.
Of course, with any downloadable content comes the smaller additions that can often get overlooked. The great thing about Dawnguard is that it comes rammed with a variety of new features. These new features are in my opinion, where the decision to buy this DLC should be made. If you're hunting vampires then you'll soon familiarise yourself with a new weapon – the crossbow. If you ditch your plain bolts in favour of the exploding frost, shock and fire varieties, then you're pretty much a vampire-hunting Zeus. The DLC back-catalogue of apparel and weaponry also features new swords, bows, axes, vampire and dawnguard armour, as well as the ability to finally fletch your own arrows and smith dragonbone weapons. There's a few new locations on offer for the avid wanderer, new enemies, the chance to change your characters physical appearance underneath the streets of Riften and you can get a really cool horse. The inclusion of horse-mount battles is also a definite welcome. The coolest features of the DLC have got to be the companions you can aquire with the dawnguard, one of which is almost too reminisent of Lord Of The Rings. 
If you've rinsed Skyrim for everything it's got then it would worth your while to get your hands on Dawnguard. If however, you're still yet to complete the game or the large quantity of side missions and sub-plot, then you can wait. Dawnguard is for the Skyrim enthusiasts who have exhausted the game of everything it already has on offer. My annoyance comes from the fact it falls pretty damn short of the "full-scale expansion pack" that Bethesda had originally promised when questioned about their initial DLC ideas. I can't help but feel disapointed in a piece of downloadable content that offers nothing dynamically new in ways of entertainment considering my initial excitement that came from Bethesda's announcement regarding the size of their DLC. In case you still aren't swayed, here's a round-up of Dawnguard's content:
If that doesn't take your fancy, Dawnguard is a piece of DLC that players will be able to wait for.