Hi Brian,
It is hard to list down what impact would be there on User side after upgradation.
Prior to upgradation , please follow steps:
a. Take BAckup of Call Manager
b. Get 8.x licenses before u upgrade.
c. Check DB Replication
One can list down what all features and integrations are working in Call Manager 6.x
a. LDAP integration
b. Any Phone Services like Extension Mobility if configured.
c. NTP syncronisation
regds,
aman