I think the displays are the assorted decks of cards, but I'm not entirely sure on that. Might be worth going onto Wizard's product site and checking a few SKUs out to be sure.
On the wizard's product site.
Thank you, DracoSuave, but I think i'm missing something... okay; here's the wotc product release page for dungeons and dragons [sorted by date]:
All Product Releases
And here are the power cards, first the display, then each of the separate class decks:
Player's Handbook Power Card Display
Player's Handbook Fighter Power Cards
Player's Handbook Paladin Power Cards
Player's Handbook Ranger Power Cards
Player's Handbook Rogue Power Cards
Player's Handbook Warlock Power Cards
Player's Handbook Warlord Power Cards
Player's Handbook Cleric Power Cards
Player's Handbook Wizard Power Cards
Martial Power Power Card Display
Martial Power Warlord Power Cards
Martial Power Fighter Power Cards
Martial Power Rogue Power Cards
Martial Power Ranger Power Cards
Now, here are the products on amazon.com in the same order:
[note the artwork for the packs on the fighter and the warlock, and also note the same artwork is on the two visible packs in the power card display]
[ame="http://www.amazon.com/Players-Handbook-Power-Card-Display/dp/0786952733/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1230181761&sr=8-1"]Amazon.com: Player's Handbook Power Card Display: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Fighter-Power-Accessory/dp/0786952237/ref=sr_1_10?ie=UTF8&s=books&qid=1230181761&sr=8-10"]Amazon.com: Player's Handbook - Fighter Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Paladin-Power-Accessory/dp/0786952660/ref=sr_1_4?ie=UTF8&s=books&qid=1230181761&sr=8-4"]Amazon.com: Player's Handbook - Paladin Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Ranger-Power-Accessory/dp/0786952679/ref=sr_1_7?ie=UTF8&s=books&qid=1230181761&sr=8-7"]Amazon.com: Player's Handbook - Ranger Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Rogue-Power-Accessory/dp/0786952687/ref=sr_1_5?ie=UTF8&s=books&qid=1230181761&sr=8-5"]Amazon.com: Player's Handbook - Rogue Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Warlock-Power-Accessory/dp/0786952695/ref=sr_1_6?ie=UTF8&s=books&qid=1230181761&sr=8-6"]Amazon.com: Player's Handbook - Warlock Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Warlord-Power-Accessory/dp/0786952709/ref=sr_1_8?ie=UTF8&s=books&qid=1230181761&sr=8-8"]Amazon.com: Player's Handbook - Warlord Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Cleric-Power-Accessory/dp/0786952717/ref=sr_1_3?ie=UTF8&s=books&qid=1230181761&sr=8-3"]Amazon.com: Player's Handbook - Cleric Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Players-Handbook-Wizard-Power-Accessory/dp/0786952725/ref=sr_1_11?ie=UTF8&s=books&qid=1230181761&sr=8-11"]Amazon.com: Player's Handbook - Wizard Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[note the artwork for the fighter and rogue, and note the artwork on the two visible packs in the display]
[ame="http://www.amazon.com/Martial-Power-Card-Display-Accessory/dp/0786952830/ref=sr_1_1?ie=UTF8&s=books&qid=1230181798&sr=8-1"]Amazon.com: Martial Power Card Display: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Martial-Power-Warlord-Cards-Accessory/dp/0786952806/ref=sr_1_5?ie=UTF8&s=books&qid=1230181798&sr=8-5"]Amazon.com: Martial Power - Warlord Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Martial-Power-Fighter-Cards-Accessory/dp/0786952253/ref=sr_1_6?ie=UTF8&s=books&qid=1230181798&sr=8-6"]Amazon.com: Martial Power - Fighter Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Martial-Power-Rogue-Cards-Accessory/dp/0786952814/ref=sr_1_4?ie=UTF8&s=books&qid=1230181798&sr=8-4"]Amazon.com: Martial Power - Rogue Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
[ame="http://www.amazon.com/Martial-Power-Ranger-Cards-Accessory/dp/0786952822/ref=sr_1_3?ie=UTF8&s=books&qid=1230181798&sr=8-3"]Amazon.com: Martial Power - Ranger Power Cards: A 4th Edition D&D Accessory: Wizards RPG Team: Books[/ame]
Okay; the only numbers that I can see that are similar on wizards and amazon are the "ISBN-13" numbers, that's it. Neither wizards nor amazon give any information about the product except for isbn-10, isbn-13, price, and product number, but that's counting both sites together. I'm thinking that the product number on wizard's site may be the SKU, but how do I determine that for sure?
Also, if wizard's product number is indeed the SKU, what do I do with this SKU information to determine whether or not the power card display will contain eight different decks or eight copies of the same deck? This is what i'm not understanding.