Re: Hosting
just my 2c 
I’m using http://www.slicehost.com for some of the wpmu/buddypress sites I’m building now. I’ve started with a 256MB slice, and will/can expand when needed to a larger/more slice(s). My configuration is/will be:
– nginx instead of apache (implemented)
– eAccellerator (implemented)
– Multi-DB from premium.wpmudev.org (implemented soon, 256 DBs)
– WP-SuperCache or WP-SuperCache-Plus (not sure which one yet)
– offload themes to S3 (maybe)
