Quite sometime back I had done a comparison between Google Chrome Extensions and Firefox Add-ons. In that, I had pointed out the the Chrome extension gallery lacks categorization, which makes it really difficult to find extensions with perform a certain set of tasks.
It has been quite a few months now, and the gallery still does not have any categorization in place. So as a user when you browse the gallery, you will come across all sort of extensions which you have no interest in, and which you could have easily avoided if the gallery had categorization.
To top it the gallery also does not segregate themes from extensions, which in turn makes it more difficult to find good themes.
3000 is definitely a big number considering that only few months have passed since the gallery went live, however, the extension gallery is still in a disarray. Agreed that you can search for extensions, but how would I know the name of an extension without browsing the gallery. If I could browse categories such as Themes, Sports and so on, I could quickly and easily find what I want. Search does not work in every place, hope you are listening Google.