Making parties seemed to be all kindsa fucked up for me last night, at least on Xbox, and I don't know if it was some kinda NAT horseshit or launch day jitters or what, but I wasn't able to party up with people I played the beta ("beeta") with just fine. We were eventually able to hack the planet, so to speak, by joining the game the other person was in and then beating the odds several times over as it kept us in the same party all night.
