Wile I am a Horde Warrior I have completed blacksmithing and gone the route of Swords. As to developing end game equipment I would say no. However you can make some very marketable equipment. This same equipment can be very effective in either pvp or pve. Major instances such as Molten Core will however give you uber equipment.
The maces you can produce in blacksmithing such as the Shatterer are very marketable and sell for good profit on the AH. I think that blacksmithing made it possibe for me to farm and craft much easier. I don't think I could have purchased my epic without artisan BS.
I chose Weaponsmith myself and haven't picked the last specialty yet. Most people I've talked to recommend Armorsmithing overall, though. I would recommend studying this in depth before making a decision.