You do not have sufficient permissions to update plugins for this site.
A couple of thoughts:
1. Unfortunately, it could be your hosting provider. Due to various server configurations, some restrict this functionality. I have had the privilege of utilizing several shared hosting providers who do not, but also the displeasure of suffering through a few that do. A switch may be in order.
2. Try changing the permissions of /wp-content/ , /wp-content/plugins/ , and /wp-content/upgrade/ to 777.
3. Maybe your account lost full admin privileges? Access your database via phpMyAdmin (most hosting providers offer this in their control panel), go to the wp_users table and find the row for your user_login . Note the ID of this row. Now, go to the wp_usermeta table and find the wp_capabilities row for your user_id . Set the value of this row to a:1:{s:13:"administrator";b:1;}
Remember that WordPress only checks for plugin updates once every 12 hours, so if you don't see any updates readily available, wait at least 12 hours.
As mentioned earlier, many of us see the plugins in need of updates identified clearly both in the Updates section (mrmist's screenshot) and the Plugins section (I'll take one the next time I see one available).
In the case of mrmist's screenshot, the plugin "Comment Timeout" is clearly identified as being available for updating, followed by "You have version 2.0.1 installed. Update to 2.1.1." As you can see, this both identifies the plugin to be updated and the version that it is to be updated too. I can assure you that the update notification in the Plugins section works no different than it did under 2.9.2.
Believe me, I wish that I could offer more than "It works for me," screenshots for proof, and the occasional "Maybe try this" response, but that's all that I have to offer. Because this functionality does work for me, exactly as it did under 2.9.2 (with the addition of the all-in-one Updates section), it's hard to speculate as to what is causing your particular problem.