Hi Mark,
Since the API can return different object types based on outputType parameter, we have decided to keep two mthods for such APIs.

getColleagues is used when we return ProfileList 
for /atom/connections.do?connectionType=colleague&outputType=profile
and 
getColleagueConnections is used when we return ColleagueConnectionList for /atom/connections.do?connectionType=colleague&outputType=connection 

On similar lines
getCommonColleagues is used when we return ProfileList 
for /atom/connectionsInCommon.do?connectionType=colleague&outputType=profile
and 
getCommonColleagueConnections is used when we return ColleagueConnectionList for /atom/connectionsInCommon.do?connectionType=colleague&outputType=connection 

To us these 2 methods 
getCommonColleagues() and getCommonColleagueConnections() sound better than getColleaguesInCommon() and getColleagueConnectionsInCommon()  

also we have renamed ConnectionEntry class to CollegueConnection class, after going through the Connections API documentaion.
http://www-10.lotus.com/ldd/appdevwiki.nsf/xpDocViewer.xsp?lookupName=IBM+Connections+4.0+API+Documentation#action=openDocument&res_title=Searching_for_a_persons_colleagues_ic40a&content=pdcontent
Refer to outputType parameter in the parameters table.