Probably the most significant addition in this release is the cargo check subcommand, which does all the type/safety checking part of rustc, but skips the LLVM part of generating the actual binary.

If you just want to make sure you code compiles, this is the command for you.

There's also a bunch of API stablilizations around Strings, Vectors etc, complete changelog: https://github.com/rust-lang/rust/blob/master/RELEASES.md#ve...

Congratulations to everyone involved on the release!