nope, the memory of Wii is enough for quite a lot save files, images, messages and VC/WiiWare games!!
but if you want audio/video files you'll have to buy an sd card (2gb) which is ultra cheap on ebay, also Nintendo said that they are going to announce something new about Wii memory, not sure when....
you can also stream media from pc, there are some quite good softwares around on the internet.....
Super Smash Bros Brawl: 1161 1357 5188
Mario Kart Wii: 1633 4506 4319
PES 2008: 1633 5820 0347
DragonBall Z BT 3: 3823 9760 9484
Pokemon Battle Revolution: 3480 2645 9186 Feel free to add me, and sent me a pm with your Friend Code!!