Whether it is 'idle rumour' or not, I don't like the idea of Apple buying Waze, and agree with many of the points that people have made.
I see an 'up-side'.
The Waze v2.x code was based on GPL (open-source) code, and suddenly when it went to version 3.x, the source was closed (and all GPL code removed). See the forum topic here:viewtopic.php?f=3&t=16933&p=150861#p150861
The rest of this post is not meant to annoy the Waze developers, it is a natural discussion/ development around open-source code. Please do not be offended.
The potential up-side of Apple (or anyone else) buying the application, is that like many other open-source projects (eg Staroffice > OpenOffice (Oracle buy-out) > LibreOffice), the original code can be forked  and this will enable the application to continue, and potentially become even better than it is now.
 https://en.wikipedia.org/wiki/Fork_%28s ... lopment%29
OpenWaze/ FreeWaze, anyone? Probably a different name, as 'Waze' is undoubtedly 'owned'. Suggestions? All this needs is a webpage, so that the project can be coordinated (Launchpad/ Sourceforge), some volunteers, a mailing list and then we can work out what code we can use. How easy/ difficult would it be to use OpenStreetMap  data, instead?
Just a thought; if anyone is interested, this would need discussion outside of this thread.