Reset all Tools from the flyout menu in any tool.
If that doesn't do it, try nuking Photoshop preferences files and forcing Photoshop to generate fresh new ones upon relaunch by holding down Command+Option+Shift (Mac) or Ctrl+Alt+Shift in Windows, immediately as you launch Photoshop, keeping them held down until you see a dialog box to which you are going to click Yes.
Thanks station_two but neither helped unfortunately.
With CC-2014 and 10.10, I couldn't get the healing brush to change into anything else, keyboard shortcuts (like v) wouldn't work, I couldn't click on another tool, etc.
As a workaround, you can cmd+tab out to finder, then back into Photoshop and you'll get your cursor back.
Thanks for your answer PK. I really expected this to work as an ok workaround.... Now I've found that I cannot even cmd+tab back into CC.
Let's say I tab out into Safari. I get the Safari window on top of CC. I tab back to CC and nothing happens.
So I have to click back into the CC window to bring it back.
Does anyone know if that is a bug that Adobe are looking into?
Have you submitted this to Apple so they can fix the bug in the OS before they release the final version of MacOS 10.10?
Just tested CC2014/PS on my MBP with Yosemite and it confirms the problem.
Will now report to Apple.