It’s a new application. You can leave CC on your computer or uninstall it. Your choice.
Also: it won't cost you more. It will use more disk space.
Because there are big changes you can try out the new version and make sure it suits you before giving up the old version.
Hmm, it doesn't really make sense for Adobe to offer two versions, but oh well. I don't know if that means they will only update CC 2014 from now on instead of CC. If in this case, I will have to try out the new version.
Thanks so much for replying!
Hmm, it doesn't really make sense for Adobe to offer two versions, but oh well.
You've always been able to keep older versions installed if you want to—I have CS3 (ID 6), CS6 (ID 8), CC (ID 9), and CC2014 (ID 10) all installed on a test drive. As Bob notes it's up to you to decide which version(s) to keep installed. I would assume InDesign 11 will be part of CC 2015.