2) Bitcoin Foundation could setup some public servers that always run the latest official version of the bitcoin client. Exchanges should then be able to verify that the transaction is legitimate to the latest bitcoin client before broadcasting them.
Do we really need a centralized service like this? Exchanges could setup their own dedicated bitcoind servers by using the code on github.
After all, it is a good idea to use a standard bitcoind server as a firewall between the in-house custom implementation and the real bitcoin network.