Well, if money is something you want to clarrify, lets split this argument into two areas.
1) Canon should give hoods with their lenses, period - its tight and really, come on.
now for the harder argument
2) The reason why the lens is more expensive has nothing to do with Nikon's 16-85. Its nowhere near the quality of the 15-85. There is an extra piece of glass in the 15-85 and therefore making it heavier. Canon uses a higher quality plastic for the lens body and correct me if Im wrong, Canon released the 15-85 with its 4 stop IS system that you now see in the 70-200 f/4IS and the 2.8IS instead of the original 3stop compensation in other Canon Lenses - this is 1 stop more than the Nikon and 2 stops more than other Nikon lenses too.
The Auto Focus on the 15-85 is MUCH MUCH faster than the Nikon, and a lot quieter (although thats kind of a moot point since they are both too quiet to notice anyway, I was just nit picking.)
In the Nikons favour, it has weather sealing at the mount but thats all I know about its seal. The Canon does not.
As for the following swipe, sure, lens hoods for EFS lenses I do appreciate but as far as EFS lenses go, Canon has been pulling out the stops for its newer releases since the image quality and sharpness has skyrocketed from older lenses like the 18-200. The 18-135 is noticeably sharper the 15-85 is sharper still and the 17-55 is just a EFS L lens. Nikon has not been making any super DX lenses, they have been too focused on their FX lenses (or whatever the Nikon version is for an EF lens)
Nikon have been truer to their users. They've honoured them with hoods and pull string bags, making a convincing arguement to stay with the camera manufacturers lenses, instead of buying third parties. With Canon the shoes on the other foot; you honour us by buying from us, and the hood, and very rarely the OEM cases.
If you look at Canon's lens releases they are making sure that their lenses are of a better IQ than that of other brands (or they are trying.) So yes Canon lenses tend to be slightly more expensive than Nikon in the EFS market - only because they are pushing their lens technology there.
If you look at the EF and L lenses, Canon has been toe to toe with Nikon - even the 70-200 2.8 on both sides are just phenomenal and hardly can be separated in terms of IQ. And Both companies dont make money from their pro market, they make it from the consumer from you.
Canon is obviously pushing and pushing their EFS line, they have 2 more choices of bodies than Nikon and a lot more lens choices in terms consumer friendly lenses like the 18-200 and the 18-135 etc. but its the 15-85 and the 17-55 where Canon want to show off.
Canon obviously wants someone with a 600D in say, 3 years time go, I want to upgrade, but I dont want to have to get a new camera.... I know, I'll get a 15-85 because its higher quality and sharper than my kit. And if L is too expensive then the 15-85 is the upgrade chouce.
Basically its a LATER lens.... Not really a kit lens you get right away, unless you want it that way. I mean I had an Olympus and I kept the kit lenses, but when I wanted to upgrade 5 years later, it wasnt a new body, it was a new lens and it was 2000 bucks, WAY too expensive but I wanted to impriove my photos not get a faster camera with snazzy features. And thats the purpose of the 15-85.
1) Olympus OM1 [Zuiko Auto-S 50mm f/1.8]
2) Pentax MZ-60 [Sigma 28-90 & 100-300]
3) Canon 7D [EF-S 15-85 & 70-200mm f/4 IS & 50mm f1.4]Leo's Flickr Page