As far as I understand, it will be possible to move between orgs in one form or another from within the Salesforce1 app. The timeline for this I understood to be based around the Salesforce Summer '14 release. However I have not seen any updates as of yet nor have I been able to track down a release date for the SF1 update. When is the next SF1 release and will it include this functionality?
I posted your question in Salesforce1 Success Community Group and got the below response
it'll be when the next versions of the mobile app hit the shelves. For Android, that'll be next month, but for Salesforce1 6.0 for iOS, it will be VERY soon
we'll be updating the Summer '14 release notes with details about new features in the Salesforce1 6.0 apps for iOS (and shortly after for Android). There will be a section that details with the new ability to switch between community and user accounts. The updated release notes will be live to coincide with the 6.0 app's availability on the App Store.
you can go thru this discussion thread for complete responses https://success.salesforce.com/0D53000001XcKe9