Cool! Glad to see some others going out for it! I'll be bringing a Monster Hunter Portable 2 Receptionist costume (because I can't NOT cosplay MH in Japan...!) and maybe Meryl Silverburgh if I get my stuff together.
sooyong, do you know what cosplay you'll be doing?
I'll definitely post up here if we end up doing something Friday.
As for cosplaying in the regular TGS areas..
I last went to TGS in 2012. In 2012, cosplayers could walk around the main area, but you could only stop to let people take pictures in the designated cosplay area, which makes sense because they're worried about traffic jams. The big video displays already cause enough people traffic problems inside.
The cosplay rules for 2014 specifically state that male cosplayers can be shirtless in the cosplay area but have to wear a jacket in the exhibition areas. So, I'm almost 100% sure you can remain in costume in the regular areas as long as you comply with the additional exhibition hall rules:
-don't have dragging skirts, cloaks etc. (fold and carry them when you walk around)
-no visible blood (cover it with something.. blood should be kept to a minimum, though, even in the cosplay area)
-no shirtless men (bring a jacket)
In case anyone needs them, here's a link to the English cosplay rules for TGS 2014.
Just to point out, some of these rules are not translated completely as they are on the Japanese cosplay rules page. For instance, you CAN wear a police or military uniform cosplay if it is clearly for a fictitious unit or group from a game ("ゲーム内に登場する架空の警察・軍隊は除く"), and you can have parts of your costume that lay on the floor as long as you pick them up and carry them while on the move.