Take out publisher's slice etc...
not only that, but also retailers and intermediary parties, transportation, etc. for boxed copies. and don't be mistaken, these things still make a big share for games. digital sales IS a minority as far as I know and most of those people posting here would be online biased towards it, so I doubt a forum enquete would bring accurate results on the total population. I think I saw the same pretty oversimplified calculation elsewhere, so I'd like to do calculating of my own:
I think assuming 100.000 digital sales and 400.000 boxed sales is somewhat realistic. I'm not sure, I even think I saw some offical using these numbers.
now, with digital sales, the publisher of course gets an amount. you know, for marketing, pre-financing, organising distribution (with retailers but also via impulse, I imagine you'd have some find of fee). but other than that ... I think no one gets a share, which is the good thing for the devs. so, out of 40$ digital price, you'd have some 25 - 30 $ remaining, at least that would be my assumption.
now, for physical copies, as said, there are a whole lot more parties taking a slice in profit. I read an ex post developer diary by frogboy after they completed gal civ 2, where he pondered and discussed all those things. very interesting stuff. I think he said that as a dev., you usually end up netting only 8$ or so for a 40$ game. considering all those shares, tbh that does not sound too surprising, but it may still be different. nevertheless, you gotta start somewhere.
so, in sum: 100.000 * 25 + 400.000 *8 = 2,5 M + 3,2 M = 5,7 M. you'd have to take away the 1M in costs in making the game, but it does sound like a positive endeavour.
and judging from how content both SD and IC were with the game, and that I pretty definately heard that it did break even, I doubt they are in serious trouble. it may get more difficult, but from it whom it does not? besides, if the next pack is again 10$, that's really a small price most people would be able to afford. if not, you have other troubles anyway.
and yes, I know the prices are rounded up, but I'm not writing .99 all the time.
edit: further the 'fear' I think is undounded, blair said they are crazy doing new things and adding stuff etc. so, I doubt it's trouble, it's just that the whole team is very productive and too busy running around explaining what they are doing. an update would be nice by now, but I'm also not unhappy if 100% effort is put directly into getting those new backstabbing tools out.