Twinking in most peoples minds always reminds them of hour long WSG battles, and dueling infront of Org/Storm waiting for a que pop.
When private servers try and interpret PvE into a Twink Private Server, they get a lot of slander saying "Twinking is all about PvP", which it is not anymore. Ever since the dreaded que time multiplying machine (A Blizzard Conspiracy), the big focus has been on XP Locked PvE. It is an accomplishment to have 5maned an instance like SFK, Gnomer, or BFD at 19.
The world of twinking has been constantly changing, even if you don't want to think of it that way. Patches that edit spells, or patches with gear updates, give twinks new things to perfect and work on to be concidered a dedicated twink. It's more than grabbing a full set of green items and spending 1000g on enchants, and it always has. The standard that has to be met to be concidered a twink has drastically been raising ever since 2005, when twinking started booming.
And the recent changes have been the most dramatic, that shifts the focus from "All PvP" to "PvP and Off PvE" to more comming "All PvE" twinks. But hopefully Cata will revive PvP with merging BG's.