People have a reason to use their accounts on Gmail, Yahoo Mail, Hotmail/Live, Facebook, Twitter, and etc. The reason why Facebook Connect has been successful is that it is an extension of an identity that many people already use on a daily basis. As long as OpenID remains just an identity provider, it will continue to lose ground. This will especially be the case in the realm of mobile, where cell phones can provide person-specific solutions in a manner that desktops so far cannot.
1) Apple was choosing between Facebook Connect and Twitter Connect for their account integration. 2) Android will naturally use Google accounts as a first choice. 3) Windows Phone will primarily use Live accounts. 4) HP/Palm and RIM need to figure out what they are going to do in this space. 5) Facebook has the ability to leverage Android for a Facebook Phone if they so choose. Currently they are instead trying to become ubiquitous across all platforms. 6) OpenID is nowhere to be found.
We will continue to see integration of this nature across all platforms. OpenID simply does not have the leverage to be successful in the long run. They're still fighting the battle in the browser, while the war is already moving higher up to the device itself.