This article lays out very articulately the current demise of the .com, *along with the simultaneous transition to the .eu domain for Sportsbook sites.
http://calvinayre.com/2011/05/24/bus...bling-domains/
I found this and two other great short reports by simply googling:
[.eu domains gain popularity with sportsbooks]
It also seems .eu is a far more inclusive domain than .ag (from a marketing standpoint), since .eu can be branded with greater efficacy worldwide.