For some reason the news that the Nintendo DS is about to get rumble support is flying low on the gaming radar.  IGN has a look at the new accessory that will come bundled with the new Metroid Prime Pinball starting next week.  Basically the DS Rumble Pak is a Game Boy Advance game pak that must be inserted in the DS's GBA slot.  We know the drill here; the Nintendo 64 utilized a similar idea for its Rumble Pak back in 1997.  Unfortunately, based on what IGN says about this new "DS Option Pak" (the official designation for DS add-ons such as this), the rumble effect is more noise and less vibration.

Either our cartridge is broken, or the DS Rumble Pak is one of the noisiest Rumble Paks Nintendo has ever built. When playing Metroid Prime Pinball, we can hear the rumble mechanism more than we can feel the rumble effects in the system. It's so loud, in fact, that it sounds like a metallic "chirp" whenever the rumble is activated. We'd rather just not put it in the system at all. Good thing it's free, because at this point we wouldn't bother buying it as an extra.

I played Metroid Prime Pinball back at E3 and to be honest I didn't notice any rumble effects.  I've heard from other people who were there that the demo units did include this new accessory, but either the DS I played didn't have the pak inserted or it just didn't work at the time.  I'm tempted to pick up Metroid Prime Pinball just to get the Rumble Pak because I always consider it to be a good deal to buy a game just to get the pack-in accessory.  I bought Star Fox 64 for the N64 Rumble Pak, Donkey Kong 64 for the Expansion Pak, and Donkey Kong Jungle Beat for the DK Bongos.  All three of those games turned out to be better than I expected, so I'm hoping that history repeats itself for this latest accessory.