With respect, I don't think it's as simple as being allowed to include binary-only code if you declare it.

The official stance from Linus Torvalds seems to be that code derived from the Linux kernel must be licensed under the same terms. I can't see how a wifi driver could be developed from scratch without it being derived form Linux code, unless the developers are extremely good at guess work

This is why binary blobs are allowed, because they aren't derived. They're blobs of cross-platform code that an open source driver hooks into.

The same Nvidia binary blob is used on both Linux and Windows. It's just that the open source component of the Nvidia Linux driver hooks-into the binary blob, which is a chunk of code that exists entirely independently of the Linux kernel.

If Nokia is writing drivers from scratch specifically for the internet tablets, then the source code must be released under the GPL. There is no question about this.

Here's what Linus has said about this issue: "The reason I accept binary-only modules at all is that, in many cases, you have, for example, a device driver that is not written for Linux at all, but, for example, works on … other operating systems, and the manufacturer … wants to port that driver to Linux. But because that driver was obviously not derived from Linux (it had a life of its own regardless of any Linux development), I didn’t feel that I had the moral right to require that it be put under the GPL, so the binary-only module interface allows those kinds of modules to exist and work with Linux." (Taken from http://www.venturecake.com/the-vmware-house-of-cards/ -- see also http://kerneltrap.org/node/1735).

You might think that Nokia got lawyers to look at this from day one but bear in mind that many commercial companies completely misunderstand Linux, and assume it's like BSD -- that the code is free for people to take and they can keep bits of it secret. Many commercial companies have been caught out this way.