Virtualbox 1.6, which was released in May 2, was the first major release since Sun took over virtualbox. All I can say is Wow!! This is perhaps the single biggest, most important open source release which will change the face of how computers are used for years to come. Hell this is even bigger than the release of hardy heron (IMO), and Ubuntu 8.04 LTS was a very important release.
One single feature of virtualbox, seamless, will make some major software completely redundant in coming years. Don’t get me wrong, seamless was possible with virtualbox since the last release before 1.6; but it was buggy, not a part of the features and needed a decent amount of hack and workaround to even get it to work. So seamless was possible, but never like this. With virtualbox 1.6 seamless is truly effortless, and well integrated, and super fast.