I'd always thought the 60D was sealed, just not as good
(i've seen the quotes a lot 1D/s>7D>5D>60D in levels of sealing).
ok, i've just found at Canon UK
, the footnote at the bottom says:
"Water/ Dust Resistance YesÂ¹"
"Water/ Dust Resistance Â¹Memory card and battery door only"
So yeah, it's not the best, but it's better than nothing. Sealed L Lenses will help a bit, i wouldn't be taking it out in downpours in any case though.
And owning a 7D+15-85, i wouldn't be running with that. not even with a 100g niftyfifty attached. I probably wouldn't even try with anything bigger than 1000D+50/1.8 (but then, that's me, i wouldn't make a mini-marathon carrying nothing, let alone camera). Giving it to family (watching on the sidelines) would be an idea, if it rains they can always stick it under an umbrella...
as for the plane, any camera would be good, i'd be more springing for a good IS lens. i'd be not recommending the 15-85 for this, unless you can use 2 hands: after 6 months mine has decided its zoom-ring is not enough to stop it creeping out or in when it's held vertically (i'll presume you're taking shots straight downwards). Too bad there's no good IS-enabled wide-primes for that job...
Overall, the 7D is a lot more camera than the 60D, especially for the AF and FPS speed, AF microadjust is a very good feature too. But for 6-year old lenses, you'll be held back a bit by slow AF motors (what are your other lenses btw?).
Hanging a camera out the side of a plane, pointing downwards, would be a very good use for the twisty-screen though (unless you take through a perpsex floor, or hang your head out to focus too?)