Or....here is a thought. Might it be good? Here's why, just off the top of my head....
The base simulation, resource management, UFO interception, research system and everything else not directly related to combat can be left exactly as it is in the original X-Com. It works fine. Upgrade the graphics and you're good.
Then do the battle sequences as small squad based combat. You can model that off a number of different games, "republic commando" being the first I can think of. On maps featuring a mixture of random generation and pre-made ships. Swapping between your troopers as you go. Are you really telling me that doesn't sound fun? Taking on Chrysalids in first person?
I agree that that it will not be the classic X-Com games (1 & 2), but they haven't gone anywhere. I've got both on my laptop. This thread makes it sound like people just want the old games with a graphical facelift and some more features. I'm not bothered about the graphics.
I loved Fallout 3, and I heard a lot of people moaning about it betraying it's roots. I think this might be the same. It won't please the hardcore fans, but the rest of us might get a good game.