The closest bike, on paper, is the CRF250L, though I still personally feel its closer or at least in between the WR250R and the new fuel injected XT250. Had that bike existed when I bought my WR250R, I don't think I would have been able to part with the extra money even though it nets a technically superior bike. That being said, I don't know if I'd trade my WR for one... but if it came down to buying new again I might be seeing red over feelin' blue. Either way I won't end up (Kawasaki) green with carb'd envy.
One bike I probably would trade for, assuming I was looking for the same style of bike, is a KTM 690 enduro. Same weight, 3x the power? Yes please!