Reading Crawler authentication in SharePoint 2013 for STS based external website I found that NTLM is still required in SharePoint 2013 for Search Crawls.
Are there other services that still require NTLM? I believe in SharePoint 2010 things like InfoPath Forms Services, Access Services, PerformancePoint, support for older, unpatched Office Clients and Excel Services may have.
I'm not sure if the switch to the new Office Web Apps Farm and other back end changes from 2010 to 2013 removed other requirements beyond search crawl.