Excited about this! I "got in the mood" by watching Prometheus (which I actually enjoyed) and Alien tonight. Aliens is tomorrow night followed by the unlocking.
I think I'll do Classic difficulty without Ironman mode. Terror from the Deep was my first XCOM and I hear it is regarded as the more difficult of the two real XCOM games so it's OK if I fail on the first playthrough, I'm used to it. I think I'll go with US for base for old times sake.
I've been watching an LP series lately to take me back to when I'd lose hours upon hours in these games and I have to say, the original games involved a LOT of tedium, from fiddling with action points to lots of repetitive click dragging in the inventory system. I think the new systems are superior here, and I just LOVE the cinematic camera when actions are played out. The old games didn't do much to tie you to your soldiers other than the few times they would pull off something heroic, or downright stupid... the new game excels here too. It seems like it's very much classic XCOM, just refined and exactly what a 21st century XCOM should be.
Now... let's just see those mod tools... AVP mod anyone?