If HRC produce the "kit" as they have indicated (or provide it as a limited edition completed customer bike as per KTM 450 RR), your blueprint holds true yes - FOR A RALLY (still fairly maintenence intensive) APPLICATION... but underneath all the bells, whistles and bodywork/tanks is STILL a CRF 450 X motor, with it's valve service intervalls, one liter or so of oil and a (relatively) high state of tune - in terms of an "every day ride/dualsport application" type bike... and THAT is where your XR 600 comparison falls short of the mark.
YES, they may well make a "rally kit" for the CRF (a' la' JVO for Yamaha, Meca for KTM's and Honda, or even Safari for a number of different late model 450 bikes) and SURE given the HRC stamp will be on it, there is every chance it will be a well thought out, quality kit at that... "bolt on" as you say. But it still is a fairly niché oriented package (HRC's own PR has always referred in terms of a customer spec/race application kit they will make available for privateer competitors.... THIS is a far cry from a production line run, series production all seasons trailbike for the masses like the XR 600 was
THAT is where your comparison of HRC CRF Rally vs XR 600 R peoples choice for over a decade is just wishfull thinking. IF Honda come up with a lower state of tune, increased service interval, dualsport 450cc derivative of the CRF engine, to base a new 450 trail model on (a' la DRZ 400E as I said before) then and only then, would I agree... yes the halcyon days of the 90's and Honda's get your rocks off in the outback fever
on an XR (or CRF 450 E... as the case might be?) may well be with us once more.
As yet, all I have heard, read or seen is that HRC intend to make a customer spec' kit available... once they've got the factory 450 Rally up and flying, a spec' decided upon and can start the production of series parts... So by mid to later 2013, perhaps you will be able to buy your "kit" to make your own JC bromance homage replica...
But any talk of an XR-like conquest of the world is - still - a long way off... no matter how red the blood in your veins run my friend.