It looks like a checkered scarf. I do think he's wearing that long face in support of Kerry though.
I understand the doubts as to whether this was intentional, and of course there's no way for me to prove it.
But I'd make this argument:
As stated in the About Islam web site I posted to, wearing Palestinian scarves "has become a symbol of support for the Palestinian people against the Israeli occupation." The site specifically mentions that ON TALK SHOWS "supporters of the Palestinian cause have begun donning this traditional scarf as a show of solidarity."
Most Americans would be unaware of this 'fashion trend.' But Matt is among the liberal elite of Manhattan, where surely people are most likely to be aware of and follow such a trend.
I think it's possible a friend or perhaps Matt's wife gave him the scarf as a somewhat-serious joke.
Also, consider all the hip, trendy people among the producers and others at the Today show. I have to believe they examine the hosts' wardrobes carefully, and again might have thought it was fun to send this 'subliminable' message.
Again, I might of course simply be wrong. But I don't think it is beyond contemplation that there is something behind it.