One of the great things about this show is the way it sets up a lot of incoming story threads that stem from earlier episodes without making it seem like it's so crowded. From the Peter Parker side of things, there were quite a few developments and some interesting tweaks from the original comic book series. Mark Raxton (or is it Mark Allen) gets a brief introduction as the former "juvee" who radiates cool and who clearly wants to make good this time around, one of those hard on the outside, soft on the inside "bad boys" no doubt. I suspect that as the season goes on, he and Mary Jane will be paired up, and considering his eventually fate as the Molten Man, that's certainly going to effect her as a character as well as do a number on Peter's relationship with Liz.
Likewise, we get the return of Harry Osborn, and not only is Peter concerned about him possibly reverting back into the Green Goblin, but he's also becoming jealous of him being Gwen's date. In some ways, there's always been a sense that in the comics, Harry Osborn was really attracted to Gwen all along and that every other person he ever dated, such as Mary Jane, Liz Allen, and Lily Hollister, were essentially just proxys of her. To see Harry actually pursue a relationship with Gwen rather than Mary Jane is more effective in this sense, not to mention that Peter, Gwen, and Harry were the original "geek squad" so that has to have an effect on their friendship in the future.
We also get some needed development of Flash Thompson, as he's starting to realize that his role as the popular jock is not all that's it cracked up to be, what with his injuries and Sha Shan apparently standing him up at his birthday party. I also liked the revelation that he and Peter were once best friends in Pre-school and that it was Peter who gave Flash his nickname, which is actually quite reflective of people who enter peer groups in high school and, I think, foreshadows a possible return to being best friends as what eventually occurs in the comics. Also, I wonder if the reason why Flash had hit on Mary Jane is because she reminds him so much of his mother, who does come across like ann older version of MJ, IMO.
Of course, on the Spider-Man side of things, we get some pretty nifty development of the otherwise hired muscle Sandman. Not only do we see a very logical and unique development of his powers, we also see that, deep down, he's not nearly the outright villain as some of Spider-Man's other rogues are. This is also in keeping with the comics in that, once upon a time, Sandman eventually realized the error of his criminal ways and eventually reformed as one of the good guys. The best example of the level his powers reached and hsi newfound attitude was when he formed himself into a giant sand castle to scare off the bullies that were teasing the little girl at the beach. And while his "sacrifice" in becoming glass after shielding the explosion of the oil tanker was dimished by his surviving, having it end with Sandman blowing away in the breeze in a similar way as the character left in Spider-Man 3 was a nice touch--and a much better send off than that movie I might add. It would be terrific if, since Silver Sable is supposed to show up in this series, that Spider-Man and Sandman meet each other again and it's revealed that he's now working for Silver Sable to bring down Tombstone and Hammerhead.
And finally, there is the return of Eddie Brock and possibly Venom. You can certainly tell that Peter's life is going to be turned upside down the way he spoke on that video camera at Flash's party (which ends up paying off the storytelling device of the video interludes of the supporting cast quite well). The only problem with Eddie stalking Spider-Man and making him paranoid enough to show him the location of the symbiote is how did Eddie manage to not only track down Spider-Man, but also not trigger his spider-sense if he doesn't have the symbiote? Likewise, where did he obtain his own pair of web-shooters? Unless the implication is that Eddie still had residule residue from the symbiote left in his system, it seems like a pretty big plot hole (and even if that was the case, why wouldn't he be able to track down the symbiote?).