Broken: 2.72a 73f5a41
Python tooltips should help developers but they do so only if python path is relativly short. Otherwise significant part of it is hidden by ellipsis. Ellipsis problem has been discussed earlier here https://blender.stackexchange.com/questions/5355/access-python-data-path-with-ellipsis/5356#5356?newreg=68386339e3b942e59dcf78740920d2f0
And it's been said there that this problem would be fixed in 2.72 release. It still isn't.
Also behaviour of CTRL+C combination with tooltips is incosistent, sometimes it copies a python path, sometimes it copies a value, all other times it copies nothing. That's really annoying.
Exact steps for others to reproduce the error
Open User Preferences, hover the search box and look at the tooltip. Then press CTRL+C and check if anything has been copied