A file doesn't exist on assets.minecraft.net

In the logs, we can see an exception which says the "1_6_has_been_released.flag" does not exist on the server.
Here is a copy of these logs :
Client> java.io.FileNotFoundException: http://assets.minecraft.net/1_6_has_been_released.flag
Client> at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
Client> at kq.a(SourceFile:237)
Client> at bhq.run(SourceFile:114)
Client> at java.lang.Thread.run(Unknown Source)

Maybe is that an anticipation of the 1.6 release ?