The RC4 attacks currently require the client being attacked to make millions of connections to the legitimate server. However, this could be done over a long period of time and the webserver may not even log an error for each attempt.
Under the right circumstances, BEAST can be exploited with a real-time practical number of connections. It was demoed on stage. Those circumstances don't include every browser configuration, but they're not very extraordinary.
The circumstances BEAST relies on involves a rapidly diminishing set of browsers. As I understand it, BEAST is less of a motivator for RC4 than Lucky 13.
Under the right circumstances, BEAST can be exploited with a real-time practical number of connections. It was demoed on stage. Those circumstances don't include every browser configuration, but they're not very extraordinary.
Does that answer your question? :-)