I've updated the list to include today's UXM #22. Of interesting note, though not discussed in the comic, is that Blackheath, Zero, and Micromax have all switched sides.
We also got a complete look at the Reservation X crew for the first time in this picture:
19 mutants are shown in the image, and there are 21(?) total mutants on the Reservation, now that Husk has returned. I see, from left to right:
Bobby, Shola, Magma, ?, Storm, Armor, ?, ?, Husk, ?, ?, ?, Warpath, Blackheath, Jimmy, Micromax, Psylocke, Mach Two. Obviously, Kitty is in the foreground. Rogue, Zero, and Black Box (AKA Network) are not pictured.
Curiously, with 6 unnamed mutants in the picture, that makes a total of 22 mutants, not 21. Now, that's most likely an error, but it's still interesting. Maybe Black Box grew some hair. Closer looks at our background mutants can be seen on that page.
Let me know if I've made any mistakes on my updates!