Hmmm, interesting question! Since it wont ship in the same case assortments, I'd expect the regular assortment to arrive and get shelved first. If Koozebane Kermit has a different DPCI (a Target product number) then he will most likely have his own seperate pegs, which would make it more likely for him to get shelved sooner. If he has the same DPCI, he may not get shelved as soon if the pegs are filled with other Muppet figures.
I would expect him to have his own DPCI though, and probably a peg or two (depending on how many pegs overall they dedicate to Muppets) for Kermit. This would allow them to keep track of that specific figure, since it wont ship with the standard line.
It really depends on how quickly they get out of China I guess. If they piggyback the exclusives right alongside the standard line, we will probably get the exclusive figures the day they shelve the standard line as well.
Your best bet is to go to your local Target and find out when they plan to reset the toy section. Once you find out when, you will get a good idea of when the Muppet figures will make it to the shelves (assuming they are in the stockroom). They reset row by row, so they can usually give you a good approximation of when they will reset a specific row, and when they will put out figures.
If they are in the middle of the reset, they may also go to the back and look for you. Typically this is against Target policy, but when they are reseting the toy area, it is more likely they make go look for you, since everything is in disarray.