I have this working in pfsense 2.0.2.
Go to Diagnostics -> Edit File, open file /etc/inc/filter.inc and change the following:
From: mwexec_bg("/usr/sbin/tcpdump -s 256 -v -l -n -e -ttt -i pflog0 | logger -t pf -p local0.info");
To: mwexec_bg("/usr/sbin/tcpdump -s 256 -v -l -n -e -ttt -i pflog0 | /usr/bin/sed -l -e 'N;s/\\n //;P;D;' | logger -t pf -p local0.info");
You have to reboot your pfsense to see the changes applied, and there no more split lines!