Maiden flight of the Arcus

The wing is totally new,

Actually, it doesn't look a "totally new" to me. I believe it's flapped as
kestrell19 said, so it propably has a little different airfoil, at least at
the flapped part, but the wing shape still looks the same, multi-trapezoidal
wing, as in DUO.

the fuselage is similar to XL (new - longer fuselage Duo/Nimbus fuselage)
However - it can be equipped with an electric self launcher so is
structurally somewhat different...

And that's a good point. Looks like the electric propulsion becomes a new
trend for powered sailplanes, and I think it is going to stay there for
much longer than the little jets. But still, couldn't they just give DUO the
battery, leaving the DUO name (same fuselage, maybe the elevator...)?
Perhaps, when they show some more specific technical info and more detailed
pictures, I will change my mind.

Maciek