If you like to have the Library file visible under Lion, you'll find that every update resets the folder to hidden status. Here's a quick way to always change that back after an OSX update.
in Terminal type the command:
This opens your hidden profile file under OS X's Unix underpinnings. Type in:
alias library="chflags nohidden ~/Library"
Type Control+x and save the file.
At the terminal prompt type:
That's period-space-periodprofile to active the changed .profile file.
Now, whenever you get a new Lion update, all you have to do to unhide the Library file is to open the Terminal and type the word 'library' and then press the Enter key, and your Library file will be back the way you want it.
[crarko adds: This takes the method given in this earlier hint and makes it a bit easier to remember and use.]
Mac OS X Hints