I got an insider tip from "Sean" that Harmonix is looking for someone with elite keyboard skills. As you can see by scrolling to the bottom of this page, Harmonix is looking to hire someone handy with the organ. Here's the job listing:
JOB OPENING: EXECUTIVE ASSISTANT-HARMONIX/Boston: 2+yrs admin exp. Strng communic & interprsnl sk; Proficient MS Word/Excel/PPT. Detail-oriented; str organ sk; fast-paced env. EOE/M/F/D/AAP. Apply www.mtvncareers.com (10/7)
Emphasis mine, as they say. Why else would Harmonix want someone whose "sk" are "str" at the organ in a "fast-paced env." (expert note charts, anyone?) if they weren't planning on including a keyboard player to Rock Band 3?