Fever, you took the words right out of my mouth. It's like they're repeating the same mistakes that they made in the 90's. We'll see Toxin in every other comic from now til 2015, and people will hate all the symbiotes.
People should learn something from Paul Jenkins. He made Fusion, who was pretty cool, but he only used him twice. He used enough stories as it was necessary to tell his story, and then left the fans satisfied. Not only that, but he tricked the fans into thinking that he was short-changing Doc Ock, but then made him the real bad guy anyway. That's some good writing.
That's what's been plagueing the symbiotes: Over-exposure and bad writing. Oh yeah, and the fact that, for about ten years, Marvel was writing stories and had no idea where they were going with them. The Clone Saga was a perfect example. Also, I hate to say it, but Maximum Carnage was another example. It was a cool story, but it really didn't need to be a fourteen-parter. Basically, we spent 28 bucks on a story that could have been a four-parter instead. I wasn't really impressed with the abundance of second-string heroes, either.