Right now I am trying to play online but the usual "busy" dialog doesn't appear, it takes me to the servers window with no servers to play on, it doesn't seem to "try" to connect at all, I tried hosting an online game, after less than a minute it kicked me with "host registration failed" message, is this something to worry about? cuz it would be a pain if only my computer fails or something; btw, just a few hours earlier I could play online... barely, since I had TONS of lag for no apparent reason.

Unfortunately Gamespy hosts the server lobby for SWBF2. They are down right now for an unknown reason. They've had server issues in the past, so it's not too uncommon. They also host the lobby for other games like Battlefield 2 and Battlefield 1942.

Edit:
Turns out the cause was known.
http://forums.bistudio.com/showthread.php?t=106050