You may think, as I did upon first seeing this Engineering thread in the forums, that Engineers have nothing to complain about. They get some of the coolest and most-wanted items in the game exclusive to their profession. In fact, as a LW/Skinner, I'm thinking about dropping Skinning when I hit 440 LW just to pick up Engineering, and pour a whole ton of gold into it just so I can get the Roflcopter and all of the other great stuff they get.
But after Wryxian gets everyone to settle down and give out just one suggestion for how to help Engineers, they all make a pretty good point: Engineering doesn't have that one self-buff that all the other professions seem to have lately. My Leatherworker can put a nice enchant on my bracers, Blacksmiths can add sockets to some of their items, and Tailors have spellthread that can be weaved into certain pieces of gear. Ashram, the original poster in the thread, actually has some good ideas along those lines -- "Electrified Armor" (reflect damage to chest) or "Laser Targeting System" (a +crit or +expertise head enchant). Other Engis just ask for their current "enchants" to stack with other enchants already on their gear.
The flip side here, of course, is that Engi can't be overpowered One person asks for Engineering to have a "significant advantage" in some bit of gameplay, and that's not the way Blizzard is handling professions -- different classes may play better or worse in different situations, but since every class can choose any profession, they've got to work across the entire spectrum (yes, even Rogues with Tailoring). But it does seem like Engineering is missing that extra self-buff that other professions picked up in Wrath.