I'm not sure if it's only me or if anyone else even noticed this. Starting with FW 6.20 and later versions the WiFi LED has been switched up by Sony. If you haven't noticed you sure will now. It drives me crazy. Anyway, the issue that I'm talking about is when you are on an active WiFi connection the LED just stays solid green instead of flashing and letting you know that data is being transfered. I guess it's not that big of a deal but it bugs me.
Thanks to some good work by PSP Homebrew dev yuh0q223 and his update to BlinkLED you don't have to worry about this annoyance anymore. After installing BlinkLED the WiFi LED will blink when there is activity. You install and activate BlinkLED in vsh.txt and game.txt.