Okay, here is the list of all unavailable iPad apps on the Australian iTunes Store, using the top 100 Paid and Free apps from the US Store. I assume the following list will be the same for the UK and other countries. Let me know if that assumption is wrong.
Name (US Rank - Category)
Paid Apps:
Pages (2 - Productivity)
Keynote (6 - Productivity)
Numbers (7 - Productivity)
SCRABBLE for iPad (12 - Games)
Mirror's Edge for iPad (21 - Games)
Need for Speed Shift for iPad (33 - Games)
COMMAND & CONQUER RED ALERT for iPad (45 - Games)
Real Soccer 2010 HD (60 - Games)
TETRIS for iPad (71 - Games)
Free Apps:
iBooks (2 - Books)
ABC Player (3 - Entertainment)
Netflix (8 - Entertainment)
Shazam for iPad (27 - Music)
eBay for iPad (29 - Lifestyle)
Yahoo! Entertainment (38 - Entertainment)
Pandora Radio (54 - Music)
Hello Baby - Pregnancy Calendar (57 - Healthcare & Fitness)
Dragon Dictation (79 - Business)
Craft Finder on iPad: Great Crafts from Disney FamilyFun (82 - Productivity)
NBA Game Time Courtside (84 - Sports)
WORLD BOOK - This Day in History for iPad (91 - Education)
White & Yellow Pages (94 - Reference)
Square (95 - Finance)
And that's all folks. Any mistakes, let me know and I will check it out.
So we have 91 out of 100 paid apps, and 86 out of 100 free apps. I would say this is pretty good so far.
Apple's apps (iWork and iBooks) will roll out to us as the iPad hits our shores.
Video and streaming apps (ABC, Netflix, Yahoo, Pandora, NBA) probably won't come around due to copyright agreements.
The big games (Scrabble, Mirror's Edge, NFS, Command + Conquer, Real Soccer, Tetris) will get to us soon I imagine.
The rest, I don't know. White & Yellow Pages is obviously a US specific app, so no need to worry about that. I'm not sure what international credit card deals will be like for Square to put into place.
I'm sure we will find out more when everything gets official in "Late May".
All information is correct to the best of my knowledge at time of typing.