a.rb

#!/bin/bash

user=clinton.paquin
pass=$(security find-internet-password -w -a "$user" -s "accounts.google.com")


curl -u "$user:$pass" --silent "https://mail.google.com/mail/feed/atom"| perl -ne '
    print "Subject: $1 " if /<title>(.+?)<\/title>/ && $title++;
    print "(from $1)"  if /<email>(.+?)<\/email>/;
' | terminal-notifier -title "Gmail" -sound default;

in my case, I had 2 messages ... so yeah, you would only see 2. Let's say you had 5 ... then it would display as follows, each message on a new line (or line break between them so they don't string together)

Subject: Message from foo (from foo@foo.com)
Subject: Message from bar (from foo@bar.com)
Subject: Message from bat (from foo@bat.com)
Subject: Message from bazz (from foo@bazz.com)
Subject: Message from buzz (from foo@buzz.com)

Looks like it's a moot point, either terminal-notifier or Notification Center appears to strip out all line breaks no matter how you format it.

I guess that's the answer I was looking for ... I tried a bunch of options and didn't have any luck. Thanks for the time, really appreciated. Congrats on going out on your own BTW, I'm a paid subscriber :)