Personally, I think dual specs is what the game has been crying out for. Having had a prot warrior/holy paladin (before the 3.0 changes) meant that trying to do anything else (dailies/pvp/etc) was just horrible, respeccing for each raid then back again just wasn't feasible.
The only shame was that they didn't get it done before WOTLK shipped, it would have made getting dungeon groups whilst levelling so much easier as all the healers/tanks could have had a dps build for levelling and the other spec for 5 mans.
AFAIK there is no way to communicate cross server. There's definitely no way to communicate between Horde and Alliance ingame and I don't believe Blizz will ever implement it - the amount of griefing and abuse would simply be too much, plus imagine the tradechat spam