WB have released a new trailer for the Harry Potter and the Deathly Hallows: Part I BluRay. The trailer includes previews of the special features that will be found on the BluRay.  You can watch the video below (Thanks TLC!):

You can pre-order Harry Potter and the Deathly Hallows on DVD or BluRay, to be released on April 11th in the UK and April 15th in the USA, at the following links:
USA:

• Harry Potter and the Deathly Hallows, Part 1 (Three-Disc Blu-ray / DVD Combo + Digital Copy)
• Harry Potter and the Deathly Hallows, Part 1 [Blu-ray]
• Harry Potter and the Deathly Hallows, Part 1

UK:

• Harry Potter And The Deathly Hallows Part 1 [DVD]
• Harry Potter And The Deathly Hallows Part 1 – Triple Play (Blu-ray + DVD + Digital Copy)
• Harry Potter and the Deathly Hallows Part 1 – Limited Edition Triple Play Steelbook (Blu-ray + DVD + Digital Copy)