I've just recently updated from 10.9.5 to PB5/GM candidate 2.0. I've tested all my apps for compatibility and all seems fine but VirtualBox. On Mavericks if I went to full-screen mode (host + F), the virtual machine occupied seperate desk/workspace and I could easily three-finger swipe back to my OS X desktop. Now it seems that behaviour changed to going fullscreen on the same desktop/workspace (just like iPhoto slideshow, I guess). This thread is just to confirm if it's not just me. If it's working as it should for others, I'll try fiddling with it. I just don't want to waste time on something that is not working for anybody. EDIT: The easy workaround is adding new desktop, moving VB window there and then going full-screen. Works just like under Mavericks.