Actually, I think you can have two different skaters doing the LP and the SP in the team event. (Up to two such substitutions total.)
It will be interesting to see what countries take advantage of that. You would have to have two skaters/teams pretty equal to risk it, I would think. But for instance Canada could send V&M for the short dance and Weaver and Poje for the long to give V&M a little breather. Russia might feel that they have two equally strong ladies.
Now that I think about it, it is not out of the question that a country might have a short program specialist and a long program specialist. That would be cool. It would add a tiny bit of team strategy, rather than just each person goes separately then tally up the results.
Yes team event has a switching policy in sp to lp but you can't do it in non team things if you have one skater. so because Russia has one man I don't think a new man could do individual if plushenko does team and then has to leave.