This one discusses the world and continent of Tyria (two separate entities with the same name).
http://www.youtube.com/watch?v=ARZWX51hYYk&feature=player_embedded
This one discusses the fall of Ascalon.
http://www.youtube.com/watch?v=X2nznISDkwk&feature=player_embedded
Discusses the 5 "main" heros of GW1.
http://www.youtube.com/watch?v=KhNHe_J-rSM&list=PL00553A085339802C&index=3&feature=plpp_video
Discusses the Chosen part of the Prophecies storyline.
http://www.youtube.com/watch?v=WnriRbcISjM&feature=autoplay&list=PL00553A085339802C&playnext=1
Here's the GW2 Guru thread that talks about both videos. Hopefully the author will make more. Both were easy to watch and understand.
http://www.guildwars2guru.com/topic/38498-guild-wars-2-story-summary/
EDIT: Added two more lore videos.
» Edited on: 2012-08-14 08:35:58