Baja Consulting is now live on SharePoint 2013 on Office 365. After waiting months for our old tenant to be upgraded, we decided to simply cancel the current subscription and sign-up again. Because of that, everything is brand new (including blog), so we apologize for anyone that got a bad link from a search engine.
For anyone that chooses this approach also, the only major thing that we ran into was Lync Federation. Others on Office 365 federated immediately (or pretty close), then after about 12 hours customer federation started working and finally Skype and MS Messenger contacts started working after about 36 hours.