The company where I work is moving it's email to Office 365. If you've not heard of it, Office 365 is a service from Microsoft that includes a number of cloud-based elements, including email, file storage and web-based versions of Word, Excel and PowerPoint.
Although I'm still working for the IT Training team, since October I've been "on loan", working with the Email in The Cloud team – and this looks set to continue for a couple of months. I'm responsible for creating end user training materials including written Quick Reference Guides and short video based tutorials. I've also created a 1-hour awareness training event which we start delivering this week.
My mailbox was migrated to The Cloud in October and I've had no issues. In fact because we're still using Outlook 2007, there were no visible differences. I am finding OWA much faster than Outlook and the ability to access my mail and calendar via my iPhone and iPad without the hassles I've had in the past, is great too.