Most people are looking beyond typical audio guides.
A few thoughts. Are you familiar with AAM Center For The Future of Museums ?
They have an excellent report, Trends Watch
Many museum people are referring to the Museum Digital Revolution (going beyond typical audio guides)
Museums and the Web is an excellent resource
An excellent paper
Are you familiar with GLAMs and the expected convergence?
Also of interest online curation
Also of interest Gallery One:
Indianapolis-Marion County Public Library Central Library branch at Children’s Museum
Learning Curve at the Indianapolis Public Library