I've been using my own devices for work since 2005. When I worked in a motorcycle shop the mechanics brought in their own tools. So why now that I'm a programmer should it be odd that I bring in my own PC and tablet?
What I would like to see companies do allocate a specified amount each year toward equipment.
As for security, Novell just released a Dropbox like application with enterprise security in mind. It's called Filr.