I have found that in any worlds created in 1.8.2 -pre2 and -pre3 the hoppers do not transfer items to another hopper or into a chest/furnace/whatever. The hoppers worked fine in 1.8.1 and 1.8.2 -pre1.
I have not tried to see if the hoppers work in a world created before 1.8.2-pre2 opened in -pre 2 or -pre 3
Environment
Current time is Jan 15, 2015 11:28:38 PM
System.getProperty('os.name') == 'Windows 7'
System.getProperty('os.version') == '6.1'
System.getProperty('os.arch') == 'x86'
System.getProperty('java.version') == '1.7.0_71'
Duplicate of MC-76562. Fixed for future version.