Real Player Universal Binary is now available - build 412.
Note that this version is not mirrored on all download sites (the London UK site hosted by demon still has build 352, PPC only). I used one of the Seattle sites to get 412. You can check which build you have downloaded using get Info (command-I).
Once you've downloaded the correct build and put the put it into your applications folder, quit all web browsers; open the RealPlayer application, go through the setup process, which will install the plugin needed to access RealPlayer content on the web, such as BBC Radio Player.
You can then change Safari to run native — unless you want to view Shockwave content!
In the finder use get Info (command-I) then click "Open using Rosetta".
Since the RealPlayer plugin is compiled to PPC code you have to ensure Safar is run under Rosetta - an application running native Intel code cannot use a PPC plugin.
BBC Radio Player uses RealPlayer, so you need the same trick to run BBC Radio player on an Intel Mac.