I am one of the few people who actually likes low pop servers, I was on one during wrath...lot less competition for ore, eternals, Netherwing eggs, time lost proto-drake, etc...and the community is nice on smaller servers, as long as you are in an active guild. The only potential downside is inability to pug content with alts (if your guild didn't have an alt run or only had one alt run) and recruiting players off-server for raid progression, although if your guild was decent you had much less competition for server first titles, etc., which infinitely helped recruitment.
You NEED an active raiding guild on low pop servers though (unless you're content with just doing cross-server content like older raids, battlegrounds and LFR), as opposed to busier servers where you can pug current content and do pretty well, aka Illidan and Mal'Ganis.
Yeah, lots of upsides to low pop servers...I don't hope they merge.