GTalk as system service
I feel the same as the original poster.....like an idiot.
I deleted the GTalk application as I was not using it and was trying to free up more space. However, I started receiving the "com.google.process.gapps" error soon thereafter.
In looking through forums and the internet, it appears that is a very common error with many causes. However, having the android sdk, it was suggested to use adb to get a bugreport.
In looking at my bugreport, I saw a lot of references to calls to the GTalk service. It is an underlying system service and it appears used by other apps as well. For example, I noticed that my GMail was not syncing consistently and I found myself manually refreshing to get it to sync.
I also noted that almost without fail, when I installed new apps in the Marketplace, I would see the "com.google.process.gapps" error.
My recommendation: Keep GTalk on your phone!