It seems pretty clear that Apple considered the market for the 17" and found it wanting. Nothing I've read indicates any 17" MacBook anywhere near ANY horizon, and it just doesn't make financial sense. Or practical sense.
Would love to read something from previous users of the 17" who doesn't now prefer a 15" or smaller btw...
Sadly I don't think it's coming back, either. I thought it might after 17" retina displays would become more feasible, but alas, I think Cook's Apple has a very particular direction, unfortunately.
I've gone from 13" (non-retina), to 15" Retina, to now an older 17". I find the additional screen real estate to be invaluable, although I will say it can look a little large if you're using it on the go (but it's more stable and comfortable, by contrast).
My girlfriend has a 13" MBA that she likes enough, but she's often using my 17" when she needs to get stuff done as the extra screen space really helps.
Not only does it split screen two windows better, but it can have 4 quarter windows (or 2 quarters and one half) effectively.
She really dislikes carrying it, though, given it's footprint, thickness, and weight at 6.6 lbs (keep in mind it's now two bodies back). I don't mind the size too much since I carry it in a backpack anyways, but it'd be really nice if it got the new form factor treatment.
Even if they just had reduced the bezels around the display and bumped the current MBP to 14.3" and 16.3" or something, that'd had been nice.