We've changed schools a couple of times, and my outgoing daughter has fared much better than I have in terms of social contact. I imagine at pick up tine, parents are engrossed in conversation revolving around kids' learning and/or social issues/teachers/school politics/middle school options. Unless parents trust you and/or know that you are dealing with the same problem, they are too fixated on discussing their own issues to open up to others. Or at least that's what I imagine; I'm at the age where I don't much care!
Anyway, to be more constructive -- if you do want to make friends, volunteer if you have time. It's cliche advice, but DD has started a new school this year, and I feel so much more involved now that I can volunteer. Also -- do parents at your new school tend to hang around a playing field and/or playground? If so, just hang out, smile/introduce yourself. I did that for two years at my child's old school, while my child played and made friends. I have to say I had some conversations, spent some time alone, learned to enjoy the peace and quiet before homework wars.

And soccer, if your chid is interested: those parents seem to be tight.