negesti and ust tubeless systems are pretty similar and most tires designed for one will work with the other. that being said i have never seen a single nagesti rim on a bike in the US... some michelin tires are designed for the nagesti system- mostly the dh ones (comp 32, 24.1, 16, 15) but the xc ones are designed for ust.
the new hot s ones are for ust i think but the older tubeless version of the hot s was for the nagesti stuff.
if you buy a tubeless tire you can run a tube in it just fine- it wont give you any trouble. if you want to run a tubeless tire on a non-tubeless rim it will take some riggin and wont work too well for trials. if you are getting a good price on the michelin tires, scoop them up- i bet you will be happy with them.