Modding for efficiency will never become "mainstream". (Mad Max type apocalypse notwithstanding!)
The general public only takes notice of us of whenever gas prices spike and media outlets look to capitalize on the low-level panic in the F150-commuting populace by running stories on hypermiling & ecomodding.
There's absolutely no doubt that the bulk of traffic and overall activity in the forum exactly tracks the "boom & bust" swings of gas prices in the USA.
But there will always be a "core" group here that thinks efficiency is a worthwhile pursuit regardless of the price of fuel or what MPG they are currently achieving - these are people who enjoy tinkering for tinkering's sake.
So if you're worried we're getting too mainstream (
you did notice this is a really old thread, right? 
), you can take heart that the price of gas has been on the decline for several months - since the latest peak back in September. Traffic/activity is following suit.
We're definitely on an "un-mainstreaming" trajectory at the moment.