This looks pretty good. Personally, I find a lot of sounds from Line6's stompbox modeler series a little goofy, but it's neat that they're putting all of them in one package for what is likely the price of two of them. Having a dedicated looper is nice, but I would've preferred a fifth stompbox with looping as an option that could go anywhere in the chain.
Squinting at those pictures, the control setup looks very intuitive. On/off for every stompbox, what looks to be a global tap tempo (though not 100% sure on that) and a whole bunch of looper controls as well as a shift button that changes everything into preset mode controls. Well done Line6.
Anyway, feature wise it seems like it's a day late and a dollar short compared to Boss's new GT-10b (parallel chains that can be controlled by dynamics - awesome). But the Line6 looks a heck of a lot easier to use... I guess it depends whether you prefer Boss's goofy stompbox modelled sounds or Line6's.
What would make me go out and buy one the second it came out is if it had the Line6 Developer's kit built-in or was at least compatible.
Does anyone know if the M13 can have multiple of the same effect running at once?