Has hip-hop hit a creative glass ceiling

The other day a friend of mine had sent out an e-mail that had a massive collection of hip-hop songs that spanned 20 years of hip-hop (thanks E!). The lists were broken down into decades. There were all types of artists that had different styles of music. They were from the east coast, west coast, down south, and there were even some memorable underground artists that were listed as well. Basically the list wasn't just the typical hip-hop list you would see today, which was refreshing. 

What I'm trying to get at it is that the lists showed the areas in which hip-hop was at its creative high point. Now before we start getting threatening comments about hip-hop artists that are doing things on the creative side, it seems as a whole hip-hop has hit a creative ceiling. 

It seems like people are trying to adapt formulas that would work for them, which is cool. For instance, you have 50 who took advantage of the mix tape. But now it seems that everyone has a mix tape. I understand that it's a way for an artist to keep their name afloat but it's kind of hard to take advantage of it when everyone else is doing it. We also have Soulja Boy who took advantage of the internet. Which again is cool because technology has definitely changed the way people hear and receive new music. Hell we even have a new president that took advantage of the internet so I can't get mad there. 

Then we have the latest thing, auto tuning. While it's great that Kanye is experimenting and trying new things to be creative, but T-Pain seemed to have that niche cornered and now everyone and I mean EVERYONE is digging into that bag right now. 

It happened to Das EFX, and a countless list of others. I know with hip-hop coming up on 30 years there's going to be artists that are influenced by the artists that came before them and there's going to be some resemblances. But taking someone else's niche, styling, flavor, or swagger and trying to make it your own is rather stale. We're talking about a genre of music that originated from break beats to become the global force it is now. You can get no more creative then that, but what happened?

What do you think? I'll step off my soapbox so you can start casting your stones now...