So we're into the migration process to the new GNOME server and are hitting concurrent users loads of around 135. We pushed the thin client updates Monday night and found one tiny regression Tuesday. It was quickly fixed and we re-pushed to that department and then upgraded yet another department last night. So far no major issues in scaling. The upgrade process will conclude on the 23rd, lots more devices to go. Once you get past the initial tuning issues, it's amazing how well this stuff scales.
For those interested, here is top running with the 135 users....very nice.