When you spectate someone in the OnLive Arena or through the Arena tab under a specific game in the OnLive Marketplace, you can now also see for how long that person has been playing that particular game. This feature comes quite handy as you can now tell how far into the game that person is, how much he sucks if he didn't make a big progress in that time frame or if he has a social life outside of OnLive gaming, which could be embarrasing for that player. But hey, you can always turn spectating off, if it embarrases you. Below is a screenshot of this new feature.
One thing that OnLive could improve is to update the time while you are spectating. Currently the time only updates when you exit spectating that player and then return spectating him.