I'm pretty sure it would work. The main functions of the new core, I think, are some new instructions (additional). If you don't update your BIOS, then Windows probably just won't know that the new instructions are available. So, it's kind of like not using the full potential of the new processor. It will still run in the motherboard, but just not with it's new features, until of course, you update the BIOS.
That is how I read into it. Your best bet would be to contact ASUS, but I bet they will say the same thing. Heck, otherwise, you would have to buy two processors if you wanted to use the Venice, one that isn't, so you can update the BIOS, and then replace that one with the Venice one after you are done. I'd say just give it a shot. It's not like you are going to be frying the CPU, it's the same socket, if they were going to change voltages on you, they would change the socket.