Yes, I think once Google+ releases their APIs (what is taking them so long) one can see hundreds of new apps popping up - not just for the web but also for the mobile version. Also the group video chat they have (hangouts) is actually Google+'s killer app - can already imagine many cool apps using it (customer support, training etc).
While we are worried that performance may be lower and costs higher - we are not sure if this would be the case. If we can get the same performance for a comparable cost (say within 10 to 15%) of what we are currently paying, we would prefer EC2 for two reasons 1) Redundancy - in case we have a problem it would be easy to restore instances and be back up online quickly 2) Flexibility - as we occasionally (2 or 3 times a year) do have peak traffic loads when we could use more servers.