There has been some discussion on the Microsoft RD mailing list lateley about managed code usage internaly at Microsoft. In response to that Kevin Schuler gave us a few managed code line counts from popular Microsoft products:

• Visual Studio 2005: 7.5 million lines
• SQL Server 2005: 3 million lines 
• BizTalk Server: 2 million lines
• Visual Studio Team System: 1.7 million lines

These products have hundreds of thousands of lines of managed code:

•  Windows Presentation Foundation: 900K lines
• Windows Sharepoint Services: 750K lines
• Expression Interactive Designer: 250K lines  
• Sharepoint Portal Server: 200K lines
• Content Management Server: 100K lines

Just some fun trivia for your amusement!