Hey folks - just want to introduce myself. I am working on the conversion of Examiner.com (a ColdFusion/SQL Server based site) to Drupal 7.0.
I am the architect of the current Examiner.com site - a top 100 US website! We rely a great deal on cacheing, obviously, which tends to take the form of MemcacheD and MongoDB plus some of the built in application cacheing of ColdFusion (like compiled classes, cached queries, in-memory classes etc.).
We run about 100 transactions a second (tends to run about 600 transactions a second at the DB level) so we have a bit of a challenge ahead of us. We support 215 Editions with dynamic page generation behind them which creates a potential of about 1 billion pages. From a block level we would probably support about 200,000 different blocks at any point in time.
There is some debate of the Drupal cache strategy but we should have that worked out soon. I am lurking in the Performance forum and have a handle on the issues we will probably run into. Would like to thank the great developers at NowPublic for their innovation with Drupal to help bring it to the enterprise level.
I will be at the San Fran conference - hope to see some of you there. Would love to hear some success stories about caching and high-volume sites for existing sites.
If you are curious - MashMeisterD is my alter-ego - http://www.MashMeisterD.com - audio mashups. :) Have a listen.