No. Google Maps will be completely gone in iOS 6. However, it is highly likely Google will release their own Google Maps on the app store soon since they just did that with YouTube.
What do you needs maps to do? I've found Apple's offering faster and just as complete for anything I use maps for. The exception is transit, but I use a seperate app for that anyways as it uses real time GPS locations of buses.
works for the majority of features you had in the built in app and if you make a shortcut to it on your Home Screen, you'll retain about 80-90% functionality
This is, of course, assuming that the final version of Apple Maps isn't to your satisfaction
Another option is simply to not upgrade to iOS 6.0 or get an Android phone, lots of options out there, no reason to get mad at Apple for doing what they feel is in the long term best interest of their company.
The Maps application no longer uses Google to source map data. That means that some services like Street View are no longer available and that mapping data in some areas won't be as good.
YouTube has been removed from iOS 6, but you can download a new YouTube App made by Google from the App Store (it'll also work in iOS 5.1.1).
Google did not make either of these Applications - they were both made by Apple and merely used Google's services.