Before I start, I'd like to point out that I did ask someone else to write this post, so that it wouldn't seem like I was self-promoting...but they didn't want to (I'm looking at you, Deyvid Petteys).
Being one of the lucky few that got into the Dawnguard Beta, I took it as my civic duty to record my entire playthrough in 720p HD with commentary. I split it by quest and the entire thing will be uploaded to a new Youtube channel and made available as soon as Dawnguard is released on Tuesday morning. If this interests you, please subscribe to the channel here:
For those of you interested in stats, you might like to know that after I was finished recording I had 9 hours, 39 minutes and 51 seconds worth of video and 144 screenshots. The total disk space used was 64.4 gigs, with 56 gigs being used by the video and 8 for the audio commentary. The total length of all of the videos after editing is 8 hours, 2 minutes and 52 seconds.
Update 6/25/2012 11:51pm CST
I'm seeing a lot of comments asking why the videos aren't available yet, or why the DLC isn't out yet, and I thought I'd try to help clarify. I am under an NDA to not release any information about Dawnguard until it is released to the public, and that means that until I see it on the Xbox Live Marketplace, I can't make the videos public. I am currently uploading the videos, but they are set to private and will have to remain so until the DLC is officially released. No one knows the exact time that the DLC will hit the marketplace, but bear in mind that times are different all over the world. In some places in the world it's already halfway through the 26th, but Bethesda is located on the east coast of the US, they're in the EST time zone, so it's likely that the release time will be based around that. On the other hand, Microsoft is located on the west coast, in the PST time zone. I don't know if the time that the DLC is made public depends on Bethesda or Microsoft, but it's likely that it will show up somewhere in the early to late morning on the 26th. Until that time, I'm sorry but I could get in a lot of trouble if I made the videos public, please bear with me and rest assured that the moment that I see Dawnguard on the Marketplace, I will make the videos public.
Also please be patient if not all the videos are available immediately, some are still uploading due to the large filesize (attributed to the videos being in 720p). If they're not all available immediately, know that they will be within the following hours.
Update 6/26/2012 5:21am CST
As many commenters have noticed, Dawnguard has been officially released, and with it comes the videos! Like I mentioned before, not every video has been uploaded yet, but they are all in the process of being uploaded and will be available over the next few hours as they finish processing. Enjoy, guys!