Doesnt seem down for me at all.
So we can then assume that since not everybody is experiencing problems at the same time, some might still be experiencing problems, this goes for both PSN & Live.
Both of these networks are widely distributed, so local issues might be down to local CDN infrastructure, local isp issues, regional issues. Maybe even not all distributed nodes have the same resources available and the same protection from overload/attacks.
CDNs are usually hosted locally with ISPs and they might be on an underpowered server under some ones desk
I do not have Live, but reliability wise, PSN has not been better or worse than anything else that I use that is hosted online.
Yes, x-mas last year was crap and it will be interesting to see if PSN & Live are better prepared this year.
Especially since attacks have been announced, if I was a dba, server admin or network guy at Sony / MS, I would have made sure to be on vacation somewhere with no connectivity.