Hello!
I've been searching this site for a while for Vanilla loading screens for Eastern Kingdoms and Kalimdor, but all I could find was conversions of the ones posted on wowwiki.
So, I dug deep in my game collection and re-installed vanilla wow and ripped the Vanilla loading screens to share with you guys as well.
The file loading screens are compatible with both Widescreen and normal monitors so fear not widescreen users!
if you want the Vanilla loading screen as well with it's original music use Mirai's Vanilla screen. He did an awesome job!
EDIT: Here are some screenshots as requested:
The actual .blp files loaded pre-use (the loading bars can be misleading as they look similar to the wowwiki one except without the fraps logo)
Eastern Kingdoms (in-game)
Kalimdor (in-game)
Enjoy!
Mediafire - Loading Screen Download
Megaupload - Mirai's Vanilla Login screen
Mirai's Vanilla Login screen thread