[chc]

I think it's pretty much just the first reason you list. Firefox has been trying to move in this direction since the introduction of the horribly named AwesomeBar, which was intended to be a DWIM button for Web navigation.

The conspiracy theory doesn't really hold up, since as far as I can tell, pleasing Google doesn't affect Mozilla's bottom line either way. The value of Google's happiness to Mozilla is substantially less than $9 million per year. The important metric isn't happiness — it's the binary "Have we avoided pissing Google off so badly that they're willing call off the deal and give up all those Firefox ad clicks to Bing?"

To go beyond the call of duty and actually try to make Google happy by making Firefox worse would be a stupid move — it would only weaken Mozilla's bargaining position with Google.