The alternate costumes are the online feature of this game. Starting the week after launch they will add hidden spider emblems each week that when you find it unlocks and alternate. The first week is Scarlet Spiderman. This info comes from the official strategy guide,
The Black Spidey suit though is for completing the game to 100%
Also the comic page collectibles are random in free roam
That's unfortunate for people who don't have online, but it's actually a pretty cool way to do it. Now I just wonder if it's an online DLC feature that will set you back 99 cents every week.... If they added more random crime AND a suit/icons to hunt for, I'd pay it in a second.
GameFOX for Gamefaqs Firefox users is a must have add-on.
another question. When you say pages are random. Does that mean all the pages or just the ones in the air? And is it random as in anywhere in the city or random like in prototype where different woi tagets wandered around a set area?