That's fantastic news! I currently use Scala for most of my personal development, but having type classes would make F# attractive enough for me to switch over. I much prefer the cleaner syntax of F#.

Losing HKT would be a shame, but that's a trade-off I would be willing to make.

Scala has never properly supported HKTs though. When I last tried it, there were multiple open issues, e.g. the partial application of type parameters. So I really don't buy the argument that Scala scores a point over F# due to HKTs. If you want HKTs, use Haskell.

It scores at least 0.7 points though. That said, it loses points elsewhere (as do all languages).

I'm curious, will Type Classes enable http://www.sparxeng.com/blog/software/an-example-of-what-hig... without needing HKT?

I really think Type Classes will address 90% of what people want without requiring deep hackery. The solutions we have with class dispatch right now are workable but awkward.