Actually, the project was all but killed under Scott Thompson. Most of the leadership team on the project got laid off in the last round and the engineers got reassigned to new projects. The announcement may have happened after Thompson left, but the decision was made months ago.

One useful side effect of being behind a NAT is security.

Out of the box, you pretty good protection against port scans from the outside, which
means you might just be able to install a Windows OS, and get updates before getting infected
by the virus de jour.

Of course, that isn't sufficient/perfect security, but it does help a lot.

Another benefit is privacy... People can't tell who in your company/home is doing
what (at least by simply sniffing packet headers).

For these benefits alone, most companies/homes probably will continue to use NAT
even if IPv6 is widely adopted.