You can now connect to a temp 1.5 server on port 25564.
This temp server is 100% vanilla, so there is no protection, no commands etc. Whatever you build there visibly is likely to get griefed. Please be careful what you do where.
If you just whitelisted on the server, please be aware that the whitelist on the temp server does not update as fast.
The map from the temp server will be the new darklands. The nether from the temp server will be the new nether. So treat it with respect, it will be around for a while.