This is going to be a plugin request, and a pretty big one but I don't think anyone else has the knowledge and resources to pull this off than you guys.
When is comes to corporate compliance, preparing for lawsuits and legal issues, WP is pretty bad. Users can delete stuff all over a wordpress/buddypress/multisite setup. I've got an enterprise-class project that I want to explore using WordPress, but one of the issues corporate compliance. When an enterprise organization gets sued, and its using WP as its intranet, the bosses in that organization need a way to search out, lock and archive anything and everything that could possibly be related to that lawsuit.
WP/BP/MU is increasingly being used as a CMS/intranet solution for organizations, but there is no decent safety system available for when things go south for the organization/company and lawyers come calling.
I want WP to be able to compete with the likes of Google Apps on an enterprise level, which has a robust lockout system that locks and protects content throughout a Google Apps setup to help an organization prepare for litigation. We need this for WP, and after watching @james do his interview on Mixergy yesterday, it was clear to me that you guys just might the understanding on how to do this. Not only that, even that mess with ServerBeach this week is an example of how this could be used.
A plugin of this nature needs an ability to search everything across WP/MU/BP, archive it and lock it so that it cannot be deleted by anyone (including a superadmin, though I understand accessing the database can always undo anything). Additionally, it should be able to monitor the system for new activity (BP activity updates, posts, bbpress posts, comments, replies, etc) for new content related to a topic that is currently under a compliance-lock and add that to the archive. No need for it to remove or hide the content (but maybe an option for it), but it needs to archive it and lock it.
In the best case, there should also be a way, even if it is only something the superadmin understands, of exporting the archive in a format that can be used and understood in court as evidence. I'm thinking automatically generated pdf files. Not saying they to be pretty, but they should contain enough identifying information to be useful.
I'm sure there is more that a plugin like this would need and I think I'm only scratching the surface of it. However, I do think that this is one of those unthought of plugins that fits a high-dollar value niche which could be one of those things that really moves WP forward as a CMS/intranet option.
I've already got a business plan in the works that would need heavy use of something like this and I suspect that there are others out there with their eyes on the enterprise market that would find a use for it too.