Just wait, in time, we'll see Nintendo bring out the 'Expansion Pak Mk. II'
It fits with ease under the Game Boy Player (Which will be required for mega ultra fun-tastic happy good time Game Boy Advance Expansion enabled games)
In fact, it's a game in itself. Woah, can you keep the GameCube stable? Watch out, it's zany! It's going to fall, woah, woah, WOAH! JENGA!!!
What with this little chunk of plastic do? Why, it'll give you an extra 251 kb of graphical POWER!
Pokemon - Yet another Stadium will be the first to take advantage of it. Now you'll be able to see Pikachu blink. NOTA ABLE TO WITHA OUTA THE PAK!!!1
Not only that, but it'll also work with 'Pokemon- Sloppy Brown' on GBA which will be needed to connect with the Expansion Pak Mk. II and Pokemon - Yet another Stadium on GameCube.
Because you can't start the game without that all wired together. In fact, it's bolted on. Pokemon becomes your GameCube. Soon, after you complete both and trade the info with 16 SP's and 57 link cables, complete with the new GC memory card 69, Pikachu will launch from your control pad slot.
Only if you have a Wave Bird though.
He'll go "AW MY NUTS"
And spill his bag of nuts. Which turns into a mini-game.
Once collected, he'll scout your room for all the right Nintendo add-ons.
If you haven't collected them all, you die. Nasty death involving 32X's and Philips CDi's. Rising from their graves and having their way with your eye socket.
OMG GO GETA EM ALL! NOW TODAY! WOAH!