I am pretty sure that the desktop packages of gNewSense, in its latest stable
release, are not updated anymore. This "belief" is justified by the fact that
this release was based on Ubuntu 8.04 LTS, which does not provide such
updates anymore. I invite anybody who would have recently used gNewSense to
confirm or infirm.
If I am right, using gNewSense does not seem such a good idea (security
risks, uncorrected bugs, etc.).
Today, Trisquel is, among the free GNU/Linux distributions, the most popular
(and it deserves it!). Parabola seems to gain many users too but requires
quite some experience in administrating GNU/Linux (and the wish to spend time
to do so).
The latest Trisquel (5.5 Brigantia) uses a rather recent Linux-libre kernel
(version 3.0)... but it may not drive your Wifi card because many
manufacturers do not distribute their firmwares under a Free license (they
are blobs in the Linux kernels that are removed by the Linux-libre project).
Taking a look at the output of 'lspci' allows to identify the Wifi chipset
and search the Web for free drivers and firmwares... but without much hope
(most free drivers already are in Linux-libre).
If no free solution can drive your Wifi card, the recommended solution is to
acquire a freedom-friendly replacement. ThinkPenguin is an excellent place
where to buy such hardware since a) it is *guaranteed* to perfectly work with
Linux-libre (hence Trisquel) and b) by using this link (the "libre" part of
the URL is important), 25% of the benefits made on your purchase are donated
to the Trisquel project.