They haven't gotten rid of the "checking for compatibility updates" dialog - which was the worst part of the Firefox upgrade process in the first place.
Until FF fixes their extension compatibility, stops breaking plugins with each release, gets rid of version verification for all the popular plugins, and finds a more streamlined way (non-modal, ffs!) of prompting you to enable/disable extensions that are now broken or require more permissions, they'll still be playing catchup to Chrome's autoupdate procedure.
Well, they're playing catch up on that, that's for sure.
But my understanding is that they're adding the necessary features one by one.
Next is silent updates (=no dialogs). This one is just "no UAC prompt".
Until FF fixes their extension compatibility, stops breaking plugins with each release, gets rid of version verification for all the popular plugins, and finds a more streamlined way (non-modal, ffs!) of prompting you to enable/disable extensions that are now broken or require more permissions, they'll still be playing catchup to Chrome's autoupdate procedure.