As someone from Microsoft who works closely with a team at HP building the actual appliances mentioned discussed here, I'd love more feedback on the HP Business Decision Appliance (HPBDA) mentioned here. The appliance is designed to support 80-150 concurrent PowerPivot users (doing what we call Self-Service BI) in a 1U server (24 cores/96GB memory) with all the storage required inside the appliance. The appliance is configured to provide backup storage initially. The HPBDA from cardboard box to production takes less than an hour to configure and the only pre-req is existing AD infrastructure.
Here are product details to learn more and an unboxing video which can help understand what we're talking about.
Considering it can take months to design and build one of these yourself starting from scratch (choosing approach/software/hardware/tuning/etc) we're hoping this enables many of you to deliver a very cool capability called PowerPivot to your own organizations with minimal effort because of this.
Look forward to hearing what everyone thinks.