Engineering is really great if you are a class with multiple roles that are one equipment change away-warriors, shamans, druids and the like, the fact that the goggles give you a great high item value slot filled for both your gear sets is really powerful. I love my Tankatronic and Furious Gizmatic goggles for PvE, they are pretty much raid quality stuff and it only took about 400g to skill up to it and 200g of mats to make for each.
When paired with mining or herbalism, use of the goggles plus a mote extractor can literally increase the productivity of herb or ore farming sessions by 50-100%. Especially if you use addon combos like Gathermate+Routes to create an optimal path for circling the zone's ore/herb/gas cloud spawn points and have an epic flying mount.
Other than that, most of the engineering stuff isn't very useful. Those two things alone make the profession worthwhile for my warrior, though.
Blacksmithing is just too expensive to level and the desirable recipes drop in places where by the time you get them you don't really need them, save for stuff like the Vortex belts and some of the other stuff. I still think there will be quite a few new blacksmith warriors next patch since people will be able to buy Nether Vortices off the AH/from badges to craft a Stormherald for arena PvP.
Engineers can't really sell much of anything before they get to the higher levels right?
Again, they sell primals from mote clouds. It's very easy, very good money.