This is not a problem of Plugin Portal - reassigning for further evaluation.

(In reply to comment #0)
> I am required to use a corporate proxy.  I am however, unable, regardless, it
> seems of settings, able to get the plugin management tool to successfully
> traverse the proxy to pull down updates, nay, even the catalog.

Please, attach the messages log from a session of IDE in which you tried to connect to updates. Thanks
http://wiki.netbeans.org/FaqLogMessagesFile

I went to the URL you provided, (to read up about the log files) and was rewarded with the following displayed in the web browser:

Unexpected non-MediaWiki exception encountered, of type "HTTP_Request2_ConnectionException"
 <table border="1" cellspacing="0">
 <tr><td colspan="3" bgcolor="#ff9999"> <b>HTTP_Request2_ConnectionException</b>: Unable to connect to tcp://www-proxy-adc.us.oracle.com:80. Error: Connection timed out in <b>/usr/share/pear/HTTP/Request2/Adapter/Socket.php</b> on line <b>324</b></td></tr>
 <tr><td colspan="3" bgcolor="#aaaaaa" align="center"><b>Exception trace</b></td></tr>
 <tr><td align="center" bgcolor="#cccccc" width="20"><b>#</b></td><td align="center" bgcolor="#cccccc"><b>Function</b></td><td align="center" bgcolor="#cccccc"><b>Location</b></td></tr>
 <tr><td align="center">0</td><td>HTTP_Request2_SocketWrapper->__construct('tcp://www-proxy-&hellip;', 10, Array)</td><td>/usr/share/pear/HTTP/Request2/Adapter/Socket.php:324</td></tr>
 <tr><td align="center">1</td><td>HTTP_Request2_Adapter_Socket->connect()</td><td>/usr/share/pear/HTTP/Request2/Adapter/Socket.php:145</td></tr>
 <tr><td align="center">2</td><td>HTTP_Request2_Adapter_Socket->sendRequest(Object(HTTP_Request2))</td><td>/usr/share/pear/HTTP/Request2.php:959</td></tr>
 <tr><td align="center">3</td><td>HTTP_Request2->send()</td><td>/usr/share/pear/HTTP/Request2/Adapter/Socket.php:350</td></tr>
 <tr><td align="center">4</td><td>HTTP_Request2_Adapter_Socket->establishTunnel()</td><td>/usr/share/pear/HTTP/Request2/Adapter/Socket.php:318</td></tr>
 <tr><td align="center">5</td><td>HTTP_Request2_Adapter_Socket->connect()</td><td>/usr/share/pear/HTTP/Request2/Adapter/Socket.php:145</td></tr>
 <tr><td align="center">6</td><td>HTTP_Request2_Adapter_Socket->sendRequest(Object(HTTP_Request2))</td><td>/usr/share/pear/HTTP/Request2.php:959</td></tr>
 <tr><td align="center">7</td><td>HTTP_Request2->send()</td><td>/space/nbwiki-webroot/wiki/extensions/NetBeans_AuthPlugin.php:217</td></tr>
 <tr><td align="center">8</td><td>NetBeans_AuthPlugin->authenticate('Pbelbin', '')</td><td>/space/nbwiki-webroot/wiki/includes/User.php:2722</td></tr>
 <tr><td align="center">9</td><td>User->checkPassword('')</td><td>/space/nbwiki-webroot/wiki/includes/specials/SpecialUserlogin.php:438</td></tr>
 <tr><td align="center">10</td><td>LoginForm->authenticateUserData()</td><td>/space/nbwiki-webroot/wiki/extensions/NetBeans_AuthPlugin.php:95</td></tr>
 <tr><td align="center">11</td><td>user_hook()</td><td>unknown:unknown</td></tr>
 <tr><td align="center">12</td><td>call_user_func('user_hook')</td><td>/space/nbwiki-webroot/wiki/includes/Setup.php:310</td></tr>
 <tr><td align="center">13</td><td>require_once('/space/nbwiki-we&hellip;')</td><td>/space/nbwiki-webroot/wiki/includes/WebStart.php:129</td></tr>
 <tr><td align="center">14</td><td>require_once('/space/nbwiki-we&hellip;')</td><td>/space/nbwiki-webroot/wiki/index.php:42</td></tr>
 <tr><td align="center">15</td><td>{main}</td><td>&nbsp;</td></tr>
 </table>

please advise.

(In reply to comment #3)
> I went to the URL you provided, (to read up about the log files) and was
> rewarded with the following displayed in the web browser:

It's a temporary problem with wiki.netbeans.org service.
The line what may be worthy for you is:
For Windows 7 - C:\Users\joe\AppData\Roaming\NetBeans\7.2\var\log\messages.log

Please, try connect to updates from IDE again then attach the log. Thanks