OneCare 2.0 has been released. You can sort of think of it as the consumer version of Forefront Client Security. It also adds in backup, defragment tasks, and a friendly-ish firewall interface. You can also control other OneCare PCs from your 'master' PC, which is nice.
Frankly, I wish certain aspects of the OneCare firewall interface were included in the base Vista firewall.
The biggest addition, at least from my perspective, is support for 64-bit. For a company that is embracing 64-bit so well with certain teams (Exchange 2007), there are other teams that seem to have trouble getting it right (the recent Live setup programs).
Oh, and unrelated to this, but noteworthy - Dell has not been a nice 'partner' when it comes to the Vista logo program and providing adequate 64-bit drivers.