As I promised then, I would let you know what data center the results went or go live on, when I hear. There are some discussions and chatter at WebmasterWorld that one data center may have Caffeine results. Google has not confirmed it, nor do all webmasters believe these are Caffeine like results.
The data center is 188.8.131.52 and you should give it a try yourself. Matt said that even if they do give out an IP address, it is possible that non-Caffeine results will show on that data center for some people. So maybe this is Caffeine and some don't see it? I am not sure - I am pretty sure Matt can confirm this IP as the data center or not - after he gets back from Las Vegas.
Forum discussion at WebmasterWorld.
Update #1: Some are saying this data center has moved to 184.108.40.206.