July 2012 - As this reply is rather old, but stills seems popular. I've written a blog post based on Apple's doco and placed it on my blog. I hope you guys find it useful.
Yes. In iPhone/iPad development the Default.png file is displayed by the device automatically so you don't have to program it which is really useful. I don't have it with me, but you need different PNGs for the iPad with specific names. I googled iPad default png and got this info from the phunkwerks site:
iPad Launch Image Orientations
To deal with various orientation options, a new naming convention has been created for iPad launch images. The screen size of the iPad is 768×1024, notice in the dimensions that follow the height takes into account a 20 pixel status bar.
Filename Dimensions
Default-Portrait.png * — 768w x 1024h
Default-PortraitUpsideDown.png — 768w x 1024h
Default-Landscape.png ** — 1024w x 748h
Default-LandscapeLeft.png — 1024w x 748h
Default-LandscapeRight.png — 1024w x 748h
iPad-Retina–Portrait.png — 1536w x 2048h
iPad-Retina–Landscape.png — 2048w x 1496h
Default.png — Not recommended
*—If you have not specified a Default-PortraitUpsideDown.png file, this file will take precedence.
**—If you have not specified a Default-LandscapeLeft.png or Default-LandscapeRight.png image file, this file will take precedence.
With universal app I had iPad splash screen showing up in simulator but not on device. The iPad would instead show the Default.png splash for the iPhone. The Default-Landscape.png and Default-Portrait.png files existing, so wth? Resolution should be correct since I created the screen captures using Window | Organizer | Screenshots and used 'Save as Default Image' for the iPad, then just renamed it.
Turns out (from my one app anyways) the two iPad screen shots have to be moved to the Resources-iPad directory. Then it all works fine. Seems obvious now, but in case anyone else has lost sleep over this...
-Larry
For Adobe AIR iOS Developers, take note that if your iPad Splash images "shift" or display and scale a second later, it's because there are different dimensions depending on what version of AIR you're using.
Default-Portrait.png:
768 x 1004 (AIR 3.3 and earlier) 768 x 1024 (AIR 3.4 and higher)
Default-Portrait@2x.png:
1536 x 2008 (AIR 3.3 and earlier) 1536 x 2048 (AIR 3.4 and higher)
As of July 2013 (iOS 6), this is what we always use:
IPHONE SPLASH
Default.png - 320 x 480
Default@2x.png - 640 x 960
Default-568h@2x.png - 640 x 1096 (with status bar)
Default-568h@2x.png - 640 x 1136 (without status bar)
IPAD SPLASH
iPadImage-Appname-Portrait.png * 768w x 1004h (with status bar)
iPadImage-Appname-Portrait@2x.png * 1536w x 2008h (with status bar)
iPadImage-Appname-Landscape.png ** 1024w x 748h (with status bar)
iPadImage-Appname-Landscape@2x.png ** 2048w x 1496h (with status bar)
iPadImage-Appname-Portrait.png * 768w x 1024h (without status bar)
iPadImage-Appname-Portrait@2x.png * 1536w x 2048h (without status bar)
iPadImage-Appname-Landscape.png ** 1024w x 768h (without status bar)
iPadImage-Appname-Landscape@2x.png ** 2048w x 1536h (without status bar)
ICON
Appname-29.png
Appname-29@2x.png
Appname-50.png
Appname-50@2x.png
Appname-57.png
Appname-57@2x.png
Appname-72.png
Appname-72@2x.png
iTunesArtwork (512px x 512px)
iTunesArtwork@2x (1024px x 1024px)
In Xcode 11, you can provide only one image with 1x, 2x, and 3x scales then set it in LaunchScreen.storyboard to fill up the screen and everything goes well!
For Example: (1242pt x 2688pt @1x)
This is the portrait screen size of iPhone 11 Pro Max which is the large iPhone screen size yet so it will give you high-quality splash screen on all iOS devices.
Update 2019 - iOS 12
I have collected all sizes needed for the splash screen. All u need is to just drag images with these sizes and drop them, Xcode will place each size in the right place.
Good luck.
Sizes :
320×480
640×960
640×1136
750×1334
768×1004
768×1024
828×1792
1024×748
1024×768
1125×2436
1242×2208
1242×2688
1536×2008
1536×2048
1792×828
2048×1496
2048×1536
2208×1242
2436×1125
2688×1242
Note
Count of required images are 26 images
but there are 6 duplicated sizes
so u will find the above sizes are only 20.