Just spoke to a retailer who gave me the number for the upcoming Metra harness for an '07 Jeep Wrangler, to replace OEM head unit. As you are probably aware, the '07 has the Can Bus 2. I know others have installed replacement head units, but I'm wondering if it's worth waiting for a plug & play harness, rather than splicing. Maybe it's not as big a deal as I think. Please advise.

I would tend to say use a harness. It makes life easier since you don't have to test each and every wire.