From the Office blog here:
Join us Friday, April 4 at 1:00pm PDT/4:00pm EDT for the first Excel-hosted AMA (what’s an AMA?) on reddit. We get great feedback and input about Excel through customer site visits, bringing customers to Microsoft, sharing on blogs and support forums, and more, but we haven’t interacted broadly in real-time–until now. We’ll start a thread on reddit.com/r/iAMA at 12:50pm PDT/3:50pm EDT and we’d love to hear from you, so ask us anything!