You log in to the "battle log" website they've created, there you get access to a web based server browser, buddies list and can view stats, setup VOIP channels (web browser plug-ins required). When you join a server the game loads in the background, while this happens "Origin" pops up to the foreground and it cycles through advertisements on EA's store. If you minimize it then BF3 starts minimized as well. I couldn't find a way to stop it from popping up.I can't really comment until I see it running. But going backwards and forwards between game and website doesn't sound like fun and adverts in your face while waiting for the game to load is even worse.
You need to leave your web browser open and have "Origin" running in the background while you play BF3.
There is no in game server browser, some people think that it was missing because it was Alpha but DICE went through all this work to make the game run with the web based frontend and "Origin". There's no way they would double their work and put a traditional server browser in game as well.
Battlefield games have never loaded fast when first released.
It sounds dumb but they might have implemented it in a intellegent way. ( But this is EA ).