I just picked up a new client who was an early adopter of Office 365 for email services. So far works great for them and they have been using OWA for a few years now.
The company saw sudden growth in the last three years, where they went from 20 or so employees to almost 100. Their local network is a mix/mash of work-groups, home groups, and a NAS. Obviously they are having problems getting files shared and hooking in network resources like shared printers and the what not, as well as management issues obviously. So for a lot of different reasons, I want to move them eventually to a domain structure. What I am not sure is can I SMTP match already existing Office 365 accounts into a fresh AD environment? Just about everything I found is migrating from existing domain to Office 365, not the other way around.
I also contemplated just letting them stay on their individual workstations (Company culture will be a hard thing to change here as well as a long entrenched "Bring your own device" policy, meaning i can't really take control of someone's personal computer) and just moving their file shares to a sharepoint site, or even a terminal server, but even then, it would still be nice to give the users one username and one password for all their accounts.
Budget wise, I didn't make any hard numbers since it is still in planning phase, but offline discussion, boss wasn't too upset of 25-50k start up cost and understands . (though a lot will be spent in getting them licensed correctly for AV, Office (either all in Volume or or all in Office 365 as an add on to the Email). Not to mention, there are a lot of layer 1 issues that need to be resolved before we can move forward on anything. (wiring is a nightmare here)