Fatal error: Unsupported operand types in /srv/bindings/0fc0490eac7742f18f1d664df86acdf5/code/includes/common.inc on line 4465

Confirmed. I followed your steps and got:

An AJAX HTTP error occurred.
HTTP Result Code: 200
Debugging information follows.
Path: /panels/ajax/editor/add-pane/panel_context%3Apage-sampe_page%3Apage_sampe_page_panel_context/two_66_33_first/block/quicktabs-sample_quicktab/form
StatusText: OK
ResponseText: 
( ! ) Fatal error: Unsupported operand types in /Users/japerry/Sites/commons2/publish/includes/common.inc on line 4468
Call Stack
#TimeMemoryFunctionLocation
10.0001746272{main}(  )../index.php:0
20.351055058016menu_execute_active_handler(  )../index.php:21
30.351155058920call_user_func_array
(  )../menu.inc:517
40.351155059824panels_ajax_router(  )../menu.inc:517
50.626874291432call_user_func_array
(  )../panels.module:1360
60.626874292048panels_renderer_editor->ajax_add_pane(  )../panels.module:1360
70.643375057624panels_renderer_editor->command_add_pane(  )../panels_renderer_editor.class.php:701
80.643375057768panels_renderer_editor->render_pane(  )../panels_renderer_editor.class.php:1449
90.796580510088render(  )../panels_renderer_editor.class.php:169
100.796580510232drupal_render(  )../common.inc:5966
110.796580511528drupal_process_attached(  )../common.inc:5905

Marking 3.4 radar.

This is fixed by updating the most recent dev version of ctools, similar to this issue:

http://aaaminnn.wordpress.com/2013/06/04/ajax-500-error-when-adding-supe...

its related to this: #1925018: Adding a renderable-array block to a page gives errors in the admin UI

http://drupalcode.org/project/commons.git/commit/a2dedf420ddf5cdf10de20b...