On March 29th, Project 100 launched, and purchased 100 Model S's for a test car share project in Las Vegas. Here's the announcement:
http://goproject100.com/
And more here:
http://tech.co/downtown-project-100-vegas-startup-buys-100-teslas-2013-04
If this isn't Elon's big news, then it's pretty big regardless - since the cars were just ordered, and not delivered, they didn't even count towards Q1's profitability!!
Seems like a pretty good bet this is the announcement this afternoon. I'm betting Tesla is underwriting Project 100 in some fashion, thus putting their money where their mouth is.