What you did in the past was to view the 'latest version' board and clicked the 'notify' button to subscribe to it.
The board is here: http://getmusicbee.com/forum/index.php?board=6.0
So when Steven posted the new v2.4 beta thread a couple of days ago, you got notified.
But there has been no beta release yet (usually an update is posted once or twice a month).
In the v2.3 thread, you can download v2.3 final if you haven't already got it.
The 'daily-build' patch for v2.4 may appear here in future (if Steven is consistent with the naming scheme):http://musicbee.niblseed.com/V2_4/MusicBee_Exe_Patched.zip
But nothing has been posted yet.
You'd only usually download the patch if you were following development in the forum and wanted to test something.