This story (and the consumer warning) SPECIFICALLY relates to bag slings, not all baby slings. There's some information about bag slings and why they're dangerous on the Slingbabies site
here.
Properly sized and positioned pouch slings, ring slings, mei tais, wraps and soft structured carriers (which will hold baby so their spine is straight, not curved) are NOT dangerous. Hope that helps set your mind at ease. If you're worried about proper positioning, explore the Slingbabies site some more or even better, get along to a Slingbabies meeting.
If anybody has a bag sling though, please, throw it out!