Yep, but there is still one unknown - the runtime. It's always nice to have option for more lumens but for how long?
If my speculations from
here: XM-L-vs.-XP-G-comparision-follow-up-to-discussions-about-XM-L-in-ZL-H51 are correct then it means that XM-L will be used mostly for better (floody) beam pattern (H501 like). The lumens gain is mostly matter of better driver (current one wastes about 45% of power as heat).
Now, I understand that some people were little disappointed with H51 beam so its great news but it would be interesting to see updated driver combined with XP-G (or XM-L but with H51 optics) - H52. It could be very nice edc light with little more throw when needed, about 250-260 lumens (with XP-G) and no visible PWM.