Where would be the correct place to talk about a grand state of python affairs? Like it or not, many use such ratings to decide which language to learn, which language to use for their next project and whether or not to be proud of their language of choice.
I think it's important for python to be popular and good. One without the other isn't too useful.
The reason python is slipping in the index is the same reason that its popularity doesn't matter (much). Wrapper generating tools, cross language interfaces and whatnot are making "polyglot" programming a pretty simple affair these days... The TIOBE index for the most part has two distinct groups: Languages that people use at work, where risk aversion are large driving forces (see java, c/++, php) and languages people use personally because they enjoy programming in them. Because the library issue for a new or less popular language is not as big a deal as it once was, people have more freedom in their choice, and that is reflected in the diversification of "fun" languages. Javascript is an outlier here, you don't have a choice if you target the browser. Nathan