The thing is, I WON'T know what I will want in 5 years because I don't know what they will have.
True, but that's what you should base your purchase off of what lasts the longest . . . . the lenses, the strobes, etc.
Well both Nikon and Canon offer equal arrays of lenses pretty much so it doesn't help to decide the brand that way.
Equal arrays of lenses that vary slightly or greatly in image quality. Canon has been renowned for it's wide-angle optics and Nikon for it's standard zooms. Now, you have Canon really pushing the Cinema lenses so if HD video with an SLR is your cup of tea you may want to look into that.
My D2xs, D2hs, D200, D80, D70, D50 are all gone, but my 17-55 is still with me.
But I would imagine the deciding factor for many serious users might come down to the fact that the Canon has a fabulous fold out and rotatable LCD and the Nikon doesn't. That Canon LCD gives you lots of options for shots the Nikon simply can't.
Terrible feature to base a purchase off of. Nice feature, but it'd have to come down to more than just the moveable LCD . . . . but then again, we are talking about consumer mannerisms.
I think you answered your own question there. You seem on the fence about owning the 60D, so return it while the D7000 price is down, and exchange it.
This seems to be the sum of it.