I know this isn't a thread about the quality of the product, but if someone is looking for one of these types of deals, I would highly recommend shelling out for the...I think they're made by Belladonna. I can't quite remember the company.
Basically what it comes down to is if you read the reviews on Amazon for the Magic Bullet...they're horribly lacking in durability. The motors are underpowered, there are plastic screws and fittings, etc. Lot of negative reviews on them just about everywhere you look. The Belladonna ones use higher quality parts and will last longer.
That being said...
Ultimately all these things really exist as are mini blenders. And for that you can get a nice multi-tooled Braun immersion blender with attachments that ultimately do the exact same things the Magic Bullet type things do, as well as versatility they don't offer--for less cost and better quality.