Whether it is Google, eBay or MSN - they all need to scale to millions of users.
How eBay manages it's storage is an extreme problem,
"eBay's storage engineering team ('Eleven people', Strong said) utilizes 2 petabytes of raw digital space on a daily basis to run the site and store its data, yet has to add about 10 terabytes of new storage every week to cover new transactions"
TechNet paper talking about how MSN scales out SQL Server with data dependent routing to partition data across a federation of servers - this is becoming a bigger issue as sites use multi-tenant data architectures.
The consumer space sometimes leads the enterprise space, especially with free software - like instant messaging, voice over IP (VOIP), blogs, etc.
Good Microsoft paper on the use of blogs and wikis in business - how they can be relevant to workers sharing events that happened on their shift to collaboration for program management.
The real winners in enterprise intranets are ones that empower the end-user to self-service themselves - this is a space that SharePoint 2007 is going to grow and grow.
Also seems Podcasting is gaining the interest of analysts, so these corporate tips should come in handy.