Unlike Ruby, Scala has a potential to be a multi-purpose language (mobile, web, enterprise) - like C# already is (Scala is more enterprisy, C# is more mobile). Unfortunately Ruby's dynamic nature is a big limitation - both in terms of error checking and performance (e.g. for mobile games).
When I see this, I kind of think what the author usually means is "Is X the new Rails?". Ruby itself was around many years before Rails existed, but didn't enjoy that much popularity. Once Rails became very popular Ruby became very popular.