Reading the comment by Meles, again I have to ask why
people write about Esperanto without even consulting Google
first?
Esperanto is not losing impetus.
Today there thousands more books in Esperanto than 20 years ago. Many thousands of books and magazines can be read and/or downloaded from the web, (all for free) ... something that wasn't possible 20 years ago.
Only 25 languages have more entries in wikipedia than Esperanto ... out of 278 languages which have wikipedias ... out of more than 6000 languages.
Somebody must be putting all those pages in the web. Add videos, music, hundreds of yahoo-groups and Google-groups, blogs, Skype, Ipernity, Facebook. If you Google the word "Esperanto" you will get more than 60 million occurrences.
If you open the page
http://www.google.com/webhp?hl=eo you will see that even Google has a search page in Esperanto.
"It retained nouns having a gender"
It does not. Same as in English it has a few words like "actor" and "actress", or "husband" and "wife", or "Joseph" and "Josephine". The rules to make these femenines are regular, more like "Joseph" and "Josephine", or "heroe" and "heroine".
"... and cases"
There is only one case in Esperanto, that, even if it is something that you have to learn, makes things more understable, and you don't need to consider word order.
"It tried to mix the Latin and Germanic languages"
Esperanto is not a mix. Words were selected by what Zamenhof though were the best known (in Europe) words for each meaning.
I had to learn English. I learned Esperanto because I think it is the right thing to do. English resulted hundred times more difficult ... even after I moved to the USA. Esperanto allows me to communicate with people all over the world.