Some of it is UCE, partially due to a couple dingbats with similar names who apparently think my gmail account belongs to them.
This isn't spam; at worst, it's bacn with a case of mistaken identity.
As someone whose full-time job is preventing spam (I work on Akismet, which checks about 380MM Web comments per day for spam), my general response to these kinds of questions is this: Fighting spam is hard because what's spam for you is not always spam for someone else, and spammers are continually changing tactics -- what worked to prevent spam yesterday may not work as well tomorrow, so it's a constantly moving target.
In my experience, GMail's filter is just ok. I see about 50 spam per day end up in my spam folder, 3 or 4 that make it to my inbox, and maybe one false positive per month (when I bother checking). That's a 94% success rate with a 0.3% FP rate (based on my ham email activity), assuming that they're not instantly discarding blatant spam that wouldn't even merit ending up in the spam folder (which they very well might be doing). If Akismet had this same success rate filtering comments on my blog, I'd have to manually mark 230 comments as spam each day instead of Akismet's missed spam average of about one per day. I don't complain about it though, since fighting spam is hard (see above).