The big difference probably will be the compute use, the big players will introduce A2A stuff sooner than later, than you don't need to login into any services per webui.
I think we will also see more streamlined things, like verified actions / signed actions, etc.
As an example, I wanted to set up users in AWS identity center so I can give view only access to bots for my infrastructure, but that requires different email addresses. I set up an alias on my existing user so I didn't have to do that, but ideally I could have accounts for agent1 and agent2.
I can usually find workarounds like this but I feel I shouldn't have to. I don't want the agents to share my permissions in general since I'm often the admin. I want to give them limited scopes whenever possible.
edit: for reference, a Google Workspace user is ~220CAD/year and a github user is ~50USD/year. That is quite expensive if I want to add a couple of agents (well over 500CAD/year).