On classifying Esperanto as a natural language

Here is an interesting paper (a pdf) from 2007 on whether Esperanto should be treated as a natural language or not, and I agree with the findings presented therein. The basic argument is that Esperanto should now be considered to be a natural language, mainly because:

1) It has native speakers (about 1000) and has had them for quite some time as well, and
2) These native speakers haven't introduced any fundamental changes to the language.

Point #2 is especially important because if native speakers had brought about any huge changes (not just sloppy -n accusative use and slightly different stress) in the language then it would still be uncertain whether the native speakers or the L2 speakers of the language would have the upper hand in the end, and the dust would first have to clear up before the language could be properly classified.

Stressing the presence of native speakers is probably something that should be done more often, in fact. There's something about a language spoken natively by about a thousand that is just that much more appealing than a language spoken by 100,000 or more people here and there, because the latter group may have varying levels of fluency, and may spend more or less time using the language depending on their mood (IALs are often a hobby and when "real life" interferes it is often set aside for more material concerns). A native speaker though generally uses the language daily with their friends and family, and is much more solid.

Classifying Esperanto as a Pinocchio-like "used to be artificial but now quite real" language would also be good for other IALs, as they could easily show Esperanto as an example of a language that went from the drawing board to real life, much in the same way that Hebrew went from a liturgical language with no native speakers to a revived and very much used tongue today. Other IALs could then market themselves as languages that yes, are technically constructed, but with enough effort will be able to become "real" languages as well.

So how would it be classified? It's not Indo-European, nor simply constructed, nor a dead language that has since been revived. Perhaps vivified would be a good term.