Yes, finally I managed to upgrade NSpeaks to WordPress 2.3. It was a only a bit painful upgrade but eventually everything fell into place. Most of plugins I used were already updated for WordPress 2.3. Those which were not updated by plugin authors were already working in WordPress 2.3. Only 1 plugin gave a trouble on WordPress 2.3 Upgrade. It was TanTan WordPress Reports Plugin.
It requires a file from wp-admin directory which no longer exists. It shows the following error on upgrading to WordPress 2.3
Fatal error: Cannot redeclare get_users_drafts()
For fixing this trouble it is only a small fix. Open wordpress-reports/tantan_reports_load.php in your plugin directory(tantan) and find this line:
require_once(dirname(__FILE__).$tmpPath.'/wp-admin/admin-db.php');
And Comment this line so it becomes:
//require_once(dirname(__FILE__).$tmpPath.'/wp-admin/admin-db.php');
That’s all. It will now work with WordPress 2.3.