- (10.10.1 Fixes this) When some dialog boxes (Open, Save, etc) open, the animation is extremely laggy.
- (10.10.1 Does not fix this) Some applications (notably JDeveloper 12c) that used to have a transparent, frameless loading screen now have a border drawn around that loading screen.
- (10.10.1 Does not fix this) Some of the older applications have badly misaligned buttons or controls, in some cases these become completely unusable.
- (10.10.1 Fixes this) Computer name keeps changing. See the full article here.
- Some shell PATH changes caused the older version of the svn executable to run instead of the newest version. This seems to affect an upgraded system only, not a fresh install.
- Sometimes clicking the delete button on an open email window does not close the window, but does delete the email still.
- (10.10.1 Fixes this) Clicking the close button on a tab does not close it immediately, there is a noticeable delay before the tab is closed, sometimes as long as 5 seconds.
- (10.10.1 Does not fix this) On many web forms pressing the Tab key opens the Web Address popup instead of selecting the next form input element.
- (10.10.1 Does not fix this) A black box sometimes overlays whatever website Safari is displaying.
- (10.10.1 Does not fix this) When downloading a file, the download indicator in the Dock's downloads folder gets stuck and detached from the folder itself causing a weird artefact to remain on screen.
- (10.10.1 Fixes this) Every time I restart it seems that iTunes turns the Notification Centre notifications back on to show me what song is playing next.
There are probably many more issues that I haven't come across. If you have experienced something that I've not covered, please leave a comment and I will add it to this list.