I think this has come up before, so I've checked and double checked, but I still can't figure out what's up.

I'm operating on
Mac OSX 10.7.2
Sibelius 6.2
Kontakt 2.2.4
VDL 2.5.2

I've copied the three .nkx files from the cd.  I think the only difference between what I've done and what the readme prescribed was that the Sibelius 6 folder was under Library/Application Support/Sibelius Software/Sibelius 6/Sounds instead of Users/[i]username[/i]/Library/Application Support/Sibelius Software/Sibelius 6/Sounds (because of how 10.7 is built?).  I've restarted Sibelius and my computer.  Any suggestions?

Good to hear!

^That solves it thanks Justin Phillips!

Navigate to Finder's Go menu > Go to Folder (or press Shift + Cmd + G).

Type the following to get to Application Support:

User Library:
~/Library/Application Support

Root Library:
/Library/Application Support

That folder ";Application Support"; is hidden in 10.7. You should be able to find it by going to the 'Go' Menu and then either 'Home' or 'Go to Folder'. It might be possible to have the files added to the folder by either quitting and restarting Sibelius and/or your computer.

I can't see that path because the only folder/files in /Users/[i]your username[/i] are

Desktop
Documents
Downloads
Dropbox
Movies
Music
Pictures
Public

The only Application Support folder I could find was under /Library

[quote author=andyk2007 link=topic=4163.msg21809#msg21809 date=1321508623]
Inside Library/Application Support/Sibelius Software/Sibelius 6/Sounds:
";SE6_SoundSet_6.0.xml"; and
";VDL_SoundSet_6.0b.xml";
[/quote]

That looks similar to the path that I've been told by Sibelius to place sound set files. Theirs is:
    /Users/[i]your username[/i]/Library/Application Support/Sibelius Software/Sibelius 6/Sounds

Are you able to get to and/or see that path?

I'm sleepy.  Anyways, 10.7 is different in how it handles the Library folder.  It is now hidden by default so maybe it was copied to another Library folder.  If I recall correctly, I had to create the ";Sounds"; folder, but all of the other folders already existed.    

I think that whether or not I open a file in the form of the template is independent from Sibelius offering me the option of choosing VDL Soundset 6.0b during playback :/

:: irrelevant info::

sorry, I was being vague about my files. They are copied into the folders prescribed
Inside Library/Application Support/Sibelius Software/Sibelius 6/Sounds:
";SE6_SoundSet_6.0.xml"; and
";VDL_SoundSet_6.0b.xml";

Under Applications/Tapspace/Virtual Drumline 2.5:
Documentation
Instruments
Multis
";Virtual Drumline 2.5_001.nkc";
";Virtual Drumline 2.5_001.nkx";
";Virtual Drumline 2.5_002.nkc";
";Virtual Drumline 2.5_002.nkx";
";Virtual Drumline 2.5_003.nkc";
";Virtual Drumline 2.5_003.nkx";
";Virtual Drumline 2.5_info.nkc";
";Virtual Drumline 2.5_info.nkx";

I think I have all the updated software that the Write Score template instructed.  Should I just try to uninstall everything and then reinstall?

The .nkx files are NOT what should be copied into the ";sounds"; folder you're referring to. Those should actually be living in the ";Virtual Drumline 2.5"; folder (the library folder itself). This is most often found at Macintosh HD>Applications>Tapspace>Virtual Drumline 2.5.

What you need to put in the ";sounds"; folder you mentioned is the XML file that came with the template. For more information on this, check the documentation that came with the template, or check in with the folks at [url=http://www.thewritescore.com]The Write Score[/url].

Are you using the template from [url=http://www.thewritescore.com]www.thewritescore.com[/url] ?

You're not seeing users/username because you're already logged in under that username.