What exactly does the corporation want to achieve with social media?
This will drive what applications are to be used or developed for the purpose. Of course once a company heads down the software development path you add a huge layer of complexity to the equation.
Using off the shelf applications (COTS) is usually the most cost effective.
Standardization is still an Information Technology best practice and for social media applications standardization is key.
If IT is going to support social media applications, the company must decide on what tools it will use and make that the standard.
If users are allowed to use non-supported applications, it will only lead to IT and user dissatisfaction/conflict and a needless increase in risk.
Now for some links to backup my pontification:
- Generic Social Media Planning Steps
- Another Generic Social Media Plan Post
- Blog Post on Social Media IT/Business Concerns
- Cisco Security Blog Post on Socia Media Pros & Cons
- Federal Guidelines on Social Media Security
Finally, when it comes down to it, a wiki may be a better alternative for an "in-house" social platform.
Microsoft SharePoint or Atlassian Confluence are robust products that fill the employee collaboration and communication niche well, with the added benefit of having a number to call if something breaks.