Here's a little bit of a downer for those hopefuls wanting to get in as media / pre-show events.
Microsoft is pretty good, do some digging on their site. And their PR is awesome, needless to say, when a NINTENDO ORIENTED SITE wants to go to the microsoft conference, usually something would be fishy -- but nope, they welcomed us with open arms, even printing us press passes with N-Sider Media on them, rediculously cool.
Nintendo however, are very picky -- they send INVITES to their media list... and getting on to that list takes some time, and A LOT of effort.
the Media badge is a blessing, it rocks the casbar on many levels... But if you ARE in the development side of the industry, do two things: 1) check if your company is exhibiting in ANY form, then you can get an exhibitor pass, and not have to pay for your way in. 2) If they aren't exhibiting, well, buy a pass... it costs a pretty penny and is pretty limited, but you're still there... It's always good to go as a group -- rally some other employees and perhaps go 'unnofficially' for your company.
Every year the IDSA gets pickier and pickier on credentials, online media needs a business license, also you need 'street credit' (eg: be recognized as established online media), and such... some people have better luck doing on-site registration, but for the most part, if you're organized and professional, you won't have a problem, especially since you SHOULD be legit

.
Every year we head down there, we usually take a wrong turn. In 2003, we ended up on Crenshaw Ave, in the freakin projects (well, ghetto, whatever), to see MATRIX RELOADED.
This year we ended up in some place OTHER than long beach (getting off at the wrong stop sucks).... But we survive. as scary as LA can be, we haven't been shot or mugged yet, just hassled by the endless bums there.
Most of the benefits of a media badge aren't printed on the e3expo site, and most people know nothing about what it can get you. Here's a tidbit of information:
at E3 2001, myself and Glen Bayer, a co-writer with me on N-Sider, walked into a 'black tie' event being held at the LUCAS ARTS private 'room' (second floor, off the actual show floor) -- we were almost being scurried out, but they saw our media badge and asked us if we needed anything.. We had mentioned we were interested in a demo reel of ROGUE LEADER. The woman left and came back with a betamax tape, then asked if we wanted to meet Julian Eccrebret (Ugh, i can never spell his name), either way, we said yes.. And after a few beers, and some idle chitchat, we were simply shooting the shit with the top guy at factor 5.
Developers absoloutely LOVE media; we got hella exclusives that day -- even confirmation about Rogue 3 being multiplayer, just because we wanted a simple B Roll.
Every year you'll find something different, some new perk, and it just adds to the fun of being there in a working capacity -- their tagline is true: It IS where working gets fun.
Any other questions, feel free to ask.