I don't think a 61 paladin could make it very long at all. with 10khp and not judging/no colossus, my health goes down pretty fast. Even if you had Pre TBC tanking epics, I don't think it'd be sufficient.
If I were you, I'd use the paladin until he can't boost effectively (VC/DM, SFK, WC, etc) then work on getting the pally leveled while you stock up rested xp on the lowbies. If you plan your leveling well (rep rewards/quest rewards/instance drops) the moment you hit 70 you can buy some of the blue rep set pieces for pretty cheap, and have at it!