That's over 300 downgrades for me - most of which come from kde-kit (I had kde-apps 17.08.2, kde-frameworks 5.39.0, and kde-plasma 5.11.1). Of particular note is the blockage of mariadb-10.2 by akonadi-17.08.1.
Other than that (which is fixable by just a mask) I don't really see anything that especially concerns me... I would like to have a non-RC version of mesa in xorg-kit though (current is 17.2.3, xorg-kit has 17.2.0_rc5).
I don't necessarily have a huge problem with all these downgrades in that nothing should break anything I have/do - but it's definitely a non-trivial annoyance. I hope that once kits are in a more stable place we'll get the option back to track gentoo-current more closely.