Just wait for them to be updated by the owner and download a new .jar file of the plugin! Please visit my Survival Server!
If plugins you use are not being updated, it could be three things: The developer has let the plugin become inactive. The developer is working on it. Have you contacted them on their Bukkit Dev thread? The developer is waiting for recommended builds for 1.2. In either case, be patient. A lot of plugins are up in the air, especially in the wake of Bukkit joining Mojang. Give it time or find an alternative.