Search autocomplete or Intellisense-like assisted search typing
Autocomplete within search for fields/facets/functions would be useful for exploration.
We shipped this! Check the blog post at http://blogs.technet.com/b/momteam/archive/2015/02/20/smart-search-with-autocomplete-amp-the-new-filter-in-operational-insights.aspx
We are working on assisted query typing to help people learn 'in product'. I will merge this with that idea that's already tracking it.
For learning, a few resources out there at the moment:
Daniele's blog http://blogs.msdn.com/b/dmuscett/archive/tags/operational+insights/