I am definitely getting one of the new units, and probably the XL. A few comments.
Wow. This new product looks amazing, and that Line6 really listened to the customers and has leap-frogged the competition. Of course, I'm assuming it will sound amazing. I am very excited to play through it, and have an XL on order.
I think the naming of the form factors is a little counter intuitive, but that's the least important. There is a benefit to being able to say "Floor" vs "LT" without ambiguity, because "Stadium" is both a product family and a SKU. Update: Erik called these "Floor XL" and "Floor" in the intro video.
I'm guessing they'll have smaller versions in the future (like the HX Stomp) given how successful that form factor appears to be.
I wish it still had AES/BEU onboard, but I do like that it has expanded digital I/O capabilities.
I wish the smaller one had scribble strips, but I suppose that the product differentiation might not support a whole separate SKU.
I always use a pedal when live, so the XL has what I need (and so much more).
I will probably sell my LT and keep using my HX Stomp when onstage space is at a premium (until and if they release a new small Stadium).
As much as we say "nobody from Line6 reads this board", the live stream suggested otherwise, so hey Line6, this ones for you!