It is possible with EFI based boot loaders from what I've seen. I was looking for something similar and ended up discovering rEFIt and rEFInd. Although it isn't

It is possible with EFI based boot loaders from what I've seen. I was looking for something similar and ended up discovering rEFIt and rEFInd. Although it isn't technically an OS it can autodetect entries from the MBR. http://www.rodsbooks.com/refind/ http://www.rodsbooks.com/refind/