This doesn't appear to be a radical redesign, as the recent KATU re-ID was. Rather, this seems to be a refinement of the older logo, integrating the typography they've been using of late in the chyron space (the lower third of the screen).
KGW's Wikipedia page has the old logo, and the entry itself has been edited to say that it was the logo used until 21 January 2008:
Today, posted in this entry on OregonMediaInsiders, fellow user Myhousemf posted this image to an open thread (and we've got to give him the credit ... we've been all over the KGW.com site and haven't found it anywhere):
What comes immediately to the eye is the depth. There's a hint of the drop shadow lifting the 8 above its background shape. What is most remarkable is the shift in the typography (though not in the 8). As pointed out, it now matches the chyron typefaces.
What I find most encouraging about this redesign is the re-introduction of the call-sign KGW into the logo, though. I'm old-fashioned in a way – when I was growing up, child of the TV generation, a TV station's corporate ID wasn't complete without a reference to the call-sign. Latterly, that's not been the case; witness all the FOX and CW stations that ID themselves as part of the network, and the CBS Mandate (which I've referred to here before). I like this not. And the Northwest NewsChannel 8 ID didn't work terribly well for me; made it sound more like a pay-tv channel.
The return of the K, G, and W to the Channel 8 logo brings a fresh bit of locativity to the logo. Having a three-letter call is something to be proud of.
(Thanks of course go to OMI for simply existing)