Even though this topic is a month and a half old, I was able to get Construct 2 running under an XP VM in Virtualbox 4.1.8 also, without issue. All I did, really, was to enable 3D and 2D acceleration, Enable VT-X support, and set the VRAM to 32 MB. Though, I am unsure if VT-X is a "requirement", it helps performance.
It runs very well so far.
My system configuration is as follows:
8GB of DDR3 ram
Geforce 7800GTX 512MB
1TB Sata HD
Fedora 16 X64
<img src="http://dl.dropbox.com/u/46287316/Construct1.png" border="0" />
<img src="http://dl.dropbox.com/u/46287316/Construct2.png" border="0" />