I am quite a cautious person though not afraid to experiment.
I currently have 11.10 Unity and 12.04 Beta 2 running on different partitions (no problems). I have learned here that Unity can run in VirtuaBox.
When I upgrade to 12.04 LTS later this month, I am curious to understand if I could also run 12.04 in Virtual Box for experimentation and test some things before I implement them into my system?
Maybe there is a better way to achieve this, without partitioning my hard drive.
In my experience it is quite a good idea to install and run a test OS in Virtual Box. But there are some drawbacks you might want to consider:
Still there are advantages that a dual boot solution can not offer:
To take full advantages of Virtual Box it is a good idea to run the latest release installable from a repository maintained by Oracle that gives you automatic updates. If you need USB2 or RDP support you also may want to install the Virtual Box Extensions (which makes it a closed source but still free version).
For running Unity, unlimited screen geometry, some 3D graphics support, and Virtual Box shared folder suport we also need to install the Guest Additions.
Let me suggest you try it out with you present 11.10 installation (or in your 12.04 Beta installation). Your virtual machines will not be touched trough an upgrade, just keep them running almost forever (I still have a machine here I built from Ubuntu 9.04).
Yes you can try ubuntu 12.04 in latest virtual box version. The latest VirtualBox 4.1.12 has support for Ubuntu 12.04 http://news.softpedia.com/news/VirtualBox-4-1-12-Has-Support-for-Ubuntu-12-04-262435.shtml.