Buying and downloading the game in Steam, I proceeded to open up the game and start playing. It seemed exactly like Dragon Age Origins, the game it is an expansion of. As a magic user, you start by doing the boring and tedious "Harrowing" quest thing. As a fighter, you start by doing some family drama bollocks including fighting large rats, thinking what a cliche this boring tripe is, and then having a character voice that fighting rats is a boring cliche. Just because you tell the player you know you are making them do your boring linear cliche, doesn't mean it suddenly isn't boring linear cliche. Anyway, the point is that it didn't seem like a new game.
I went back to the main game menu. No sign that it was Origins, and not Awakening. The "Other Campaigns" item was disabled. The Windows system tray icon was the Awakenings one, not the Origins one. How frustrating. So I googled something like "getting dragon age awakenings to actually work in steam". Bingo, some mostly tangential jibber jabber and a hint to run some application to get content registered.
Once you have loaded the game, at the main menu for the game under "Load" will be an entry marked "Other Campaigns". Choose this and select the "Dragon Age: Awakening" campaign.No dice.. "Error opening file for writing" "Results [-1] [Failed to load XML: ]"
If you are unable to access the "Other Campaigns" menu, please verify the GCF for both Dragon Age: Origins, and Awakening:
Title: Verifying Game Cache Files (GCF)
After the verification is complete, navigate to the folder where Dragon Age is installed (by default C:\Program Files\Steam\steamapps\common\dragon age origins\)
Find the folder marked "redist", and run the following files:
Start the game, and re-test the issue.
What kind of Mickey Mouse outfit is this? Stuff you bought doesn't work, so you have to go run two applications that you barely understand the purpose of, and then they do not work for inscrutable reasons? I'm a computer games programmer and I barely understand this.
Some googling for the error message, and I stumble across some other unfortunate souls who have had the same problem as myself and without the aid of the shysters who sold them this polished turd, have worked out how to work around this DRM facilitated hoop jumping.
I searched around in the Steam and Documents folders and found all the needed .xml and .exe files. The only thing is, after running the command in command line, the "Other Campaigns" option IS STILL grayed out. The window appeared and said that everything worked fine and that the xml files were updated. It even gave me the Result  output, which im pretty sure means it was sucessful. I have no idea what is wrong.Ah! It was that simple all along :-) In my case, I had to replace "Program Files" with "Program Files (x86)", but that's a minor change.
Here is the command I used:
"C:\\\\Program Files\\\\Common Files\\\\BioWare\\\\saferun.exe" "C:\\\\Program Files\\\\Steam\\\\steamapps\\\\common\\\\dragon age origins\\\\redist\\\\DAO_UpdateAddinsXml.exe" /addins="BioWare\\\\Dragon Age\\\\Settings\\\\addins.xml" /manifest="C:\\\\Program Files\\\\Steam\\\\steamapps\\\\common\\\\dragon age origins\\\\addins\\\\dao_prc_ep_1\\\\manifest.xml"