I've noticed an insidious trend infiltrating the sixth year participants that's far worse than the so-called sophomore slump. People are starting to second guess themselves, wonder why they're doing Nano at all, what the point of this whole thing is. After all, a sixth year has completed Nano five years in a row. What more does one have to prove? The prospect of doing Nano for the rest of their lives is daunting. They don't like how Nano has evolved from the clunky but intimate site back in 2001 to the now chaotic behemoth that is the current forums. The newbies are driving them up the wall and it seems like no one is taking Nano seriously any more.
Some sixth year participants are getting Nano fatigue.
My only suggestion is the following (which I've also posted on the forums): I think the trick to approaching Nano as an alumni is to approach every year as if it was your first. Thinking about previous wins or losses can either give you a sense of inflated hubris or make you spiral down into the depths of depression--both of which are NOT GOOD. Also, take stock on what's making Nano not fun for you any more--and make sure you stay away from that. You might even have to consider not doing Nano for a year.
Otherwise, I don't know what to say. If any seventh year participants are around (or even exist), I haven't seen them posting. And the only eighth year, Chris Baty, is so out of the realm of most Nano-ers that any advice that he gives can only be taken generally.