It makes sense for mobile carriers to get involved in the EHR arena. However, the way I see this done is via cloud-stored EHR info that is accessible through a handset; how else would you carry the record should you decide to move to another carrier?
I still think it is far fetched for a mobile carrier to roll out an entire HIS application though. There are so many verticals (all, practically) that make use of mobile communications one way or another, should mobile communications providers create solutions for everything?
And a 'global' mEHR, while a nice idea indeed, I think will be always hindered by competing standards and lack of acceptance - after all, even the mobile infrastructure worldwide is fragmented, CDMA, GPS, etc. Why would the application layer be any different?
Worth keeping an eye on though.