From what I gather, you select a server to join, loads the map while letting you continue to web browse. Average load time is reported as 20-30 seconds. Lets be honest, remember some of the load times for BF2 when it was first released? We're talking damn near 2 minutes for some maps.
Edit - You don't have to close the game to change servers, just alt-tab. If it works better than an in-game browser, I will not be disappoint.