vulnerabilities in managed code

[wshepherd () mail com]

I read an article by Larry Seltzer titled "Death of Native Code".  It made me wonder, if a complete OS was written in 
managed code, would it require a VM?  if so, wouldn't the VM need to be written in native code?  There isn't alot of 
information about vulnerabilities in managed code, what types of vulnerabilities can we expect to see in the future?  
Will it mean the end of buffer overflow type bugs?  Just curious as to what people think about this.