Helvetica Neue Medium.

Here's a fairly standard wordmark enlarged from a government-supplied Adobe Illustrator file.

Here's a larger sample.

> What happened to that classy Baskerville Old Face mark?

You mean this beauty? Oh, it still gets kicked around the various hallways of bureaucracy. The Baskerville mark is basically the government's happy, shiny corporate logo, whereas the Helvetica Neue treatments are departmental identifiers. You can get your fill of Canadian government logos, symbols, word marks, and assorted style guides here:

http://icnet.ic.gc.ca/publication/

Here's my favourite of the bunch, the Federal Identity Program, complete with before and after comparisons of 'recent' updates. Be sure to check out the nearly 70MB worth of downloadable PDF fun as well.

I did a double take when I saw those coats of arms--I thought they were V-8 engines at first.