I got those at launch! I think the ones you're talking about are the official BD & A silicon wiimote skins... they've actually got the Nintendo seal of quality on them!
... doesn't mean a thing. Oh, they're not bad. It's awesome to have a black, blue, green and pink wiimote, and they've got snazzy Nintendo logos on em (Zelda triforce emblem, Wii logo, Yoshi, Peach, respectively). But they'll probably last maybe 3-4 years, because even Silicon tears.
What's MORE important is your wiimote battery solution. Some people use those recharger stands that come with custom rechargeable battery packs. Depending on the placement of the recharge port, these things are probably incompatible with Wiimote skins. (can't charge your battery through silicon skins!) I use regular rechargeable AA batteries, so I'm fine there. But STILL, whenever I switch batteries, I have to peel off the wiimote skin, then peel it back on. It's not too bad, and I've become quite adept at slipping the things on and off, on and off, on and off... but some people will probably get irked by it.
Oh, and not even wiimote skins can protect your wiimote from dust. It CAN still get dusty in the areas the skin doesn't cover... and the wiimote does get a little bit slippery because I suppose the silicon skin degrades onto ity a bit... but that just makes it easier to slide the skin on and off!