Thanks for the responses -- I ended up gambling on a purchase last night and it runs on my Toshiba NB205, which is single-core. I turned everything off that I could and it definitely slows during the AI "thinking" turn, but otherwise it works pretty well!
Really glad I bought it too. I've only played the tutorial and the first campaign mission, but in my first try in the campaign I had two of my guys slaughtered on the first turn, but I somehow spun it around in the end and had my last guy take out four machine gunners in the last two turns. <3 I'm not much of a PC gamer (naturally, since I have a netbook!) but this is a really awesome blend of turn-based and real-time strategy.