Same happened to me and after several hours of panic and Googling my butt off, I figured it out. Here's what worked for me:
1. Go into your Time Capsule settings via Airport Utility, open Network Mode and turn off all wireless in your Time Capsule only.
2. Turn off the wirless on your Mac.
3. Connect your TC to your computer via an ethernet cord.
4. Restart your computer.
NOTE: When it restarts, the info on the TC will be unavailable for a short time. Don't panic, it should show up after five minutes or so.
5. Go to your Finder and look for the TC listing. Open it and (hopefully) see the file marked 'Data".
6. Click that to open it. Look for the user you need to restore. Click the user file just as you would any external drive and look for the backup date you need.
7. Drag files from the TC to your desktop.
8. Open that file and it should have all your files on there. Just drag them to your desktop and give them time to copy from the TC to the desktop.
NOTE: The files copy much faster via a tethered connection so it won't take too long to copy what you need.
This is obviously a major glitch with Time Machine in Yosemite. I tried a lot of different ways to connect with my TC wirelessly but the connection was spotty at best and the TC never really gave me the option to restore my files.
BEST ADVICE: Don't relay on Time Machine to restore files on a clean install from Mavericks to Yosemite. Use Super Duper, it never fails.
I haven't gotten around to actually trying 'Restore' with the setup I have going at the moment, but I'll give it a try after I've copied everything I need.
I'd be interested to hear what other peoples experience were with trying this tact with the Time Machine backups. Good luck.