The Stans (no tubes) Flow is designed for exactly that.. No tubes. So it does have a kin of lock in bead around the rim. The only thing i can see that it doesnt have is the spoke eyelets. And of course you need to run the "yellow tape" as the rim still has spoke holes. But that is no problem.
The lip is slightly different to the Mavic version, but works just as well as its a lot shallower where the tyre bead sits in so it doesnt have much room for movement.
I run the Stans Arch on my XC bike which is the same rim just narrower for xc use, and it was a cinch to run it tubeless with the Schwalbe tires i have. Never had a problem.
I just wish the Stans Flow came in 36h so i could lace it to these spare 36h Hadleys i have sitting here