For one thing, they're specifically keeping Labs as part of Alphabet directly, rather than as a sub-company. That seems like recognition that experiments shouldn't have to immediately pan out or immediately become self-sustaining.
For another, they've said nothing about how they plan to handle IT and infrastructure. Though that'll certainly be interesting; they'd be foolish not to take advantage of the Google datacenter and cloud services to accelerate new projects, for instance.
The recent release of kubernetes into the public domain seems to align with this. Add to that Google's cloud services and you have infra that can be used by the independently spun off orgs.
For another, they've said nothing about how they plan to handle IT and infrastructure. Though that'll certainly be interesting; they'd be foolish not to take advantage of the Google datacenter and cloud services to accelerate new projects, for instance.