The term "lifestyler", I've heard, was originally intended as a negative term that some anti-lifestyler once used (before
Burned Furs, even). These days, some lifestylers are offended by being called "lifestylers", but it seems most don't even care these days. =)
"Lifestylers" tend to be viewed by some people as, uhm, crackpots. However, from what I've seen, the stereotypes about lifestylers are greatly exaggerated.
So what qualifies as a lifestyler? Personally, I'm just a furry who feels close to wolves; Rather than roleplaying (as most fans would do regarding their personal characters), I consider my furry alter ego to be more like an ideal I try to strive for - it'd be really cool to be him. And to be a lifestyler, even less might be required...
And you don't need to be a lifestyler to be a "furry", of course. Feel free to be enthralled by furry stuff in general, nobody isn't going to come to tell you you aren't "furry enough" or something. =)
I don't go out and howl at moon if that's what you're thinking. =) I'm perfectly aware I'm not an animal or a furry in RL, and I think the rest of the lifestylers know that too.
Lifestylers seem to hang out in alt.lifestyle.furry and YiffNet's #alf. Regrettably Locandez' excellent page is down, but http://www.yiffle.com/ has good links =)