Many people confuse community-based customer service with crowd-sourcing customer service, but in fact leveraging hyper-sociality in customer service is not the same as crowd-sourcing your customer support activities.
In some rare cases there may be enough passion around your offering or a critical mass of users surrounding your products so that you can crowd-source customer service. In most cases, however, your support activities will remain at the center of the customer service community, and be amplified by the community, not replaced.
Microsoft may be able to turn every single one of their support articles into a wiki and expect decent results from co-creating those support articles with their users. For most companies with fewer users this could end up in disaster – with tons of inaccuracies, stale articles, or worse, content that could expose you to liability.