MMO-Champ had a post today with good news for Engineers! Looks like Blizz will be giving us some serious love in Cataclysm with bonuses similar to the Jewelcrafting Dragon's Eye gems.
It looks like we'll have bonus items called Cogwheels and Hydraulic Pumps which give +132 to certain stats. This will certainly be a nice boost for Engineering, which currently is regarded as more of a 'fun' profession rather than a useful one (though I still find my Rocket Boots to be invaluable in certain fights!). The mana-injecting belt should be useful as well; I already love my Runic Mana Injectors, and with mana conservation becoming more important in Cataclysm I'm sure the belt enchant will be a great help.
The Cogwheel/Hydraulic Pump bonuses are as follows:
-Fractured Cogwheel: +132 Mastery Rating
-Quick Cogwheel: +132 Haste Rating
-Smooth Cogwheel: +132 Critical Strike Rating
-Subtle Cogwheel: +132 Dodge Rating
-Flashing Hydraulic Pump: +132 Parry Rating
-Precise Hydraulic Pump: +132 Expertise Rating
-Rigid Hydraulic Pump: +132 Hit Rating
-Sparkling Hydraulic Pump: +132 Spirit