Almost all of the best Java developers that I know (including many who ran Java user groups, podcasts, started well known projects) would choose to use Scala on a new project rather than Java. Given Scala's present state (many performance problems were ironed out in 2.8.0), I simply don't see a single reason not to do so.

It's quite puzzling why the author of the parent article lumps it in with Ruby as the two aren't very similar.

On the other hand, I've seen a friend who's a good (but not great - and he's well aware of it) developer, but is rather entrepreneurial (quit a very well paying job to work on his own project with no external funding) was very surprised after I told him Scala is statically typed. Apparently Java developers almost develop a sort of a Stockholm syndrome that leads them to believe that "if it isn't verbose and limiting, it must be dynamically typed and slow".