Hey all, just to those talking about the saves - You can actually remove the GFWL part of the save files (if you still have them) and I can confirm (for Arkham City at least) that it allows the saves to be transferred into the new Steamworks non-GFWL edition. Here's how to do it (copied in part from the steam community thread):
1. Grab a copy of a hex editor of your choice - I used the free "tiny hexer"
http://www.softpedia.com/progDownload/tiny-hexer-Download-35737.htm
2. Find your existing save files, they will be named "GFWLUserID-saveX.sgd" where X is the save slot number, and just copy them to your Desktop or somewhere you can work on them. Locations they might be are (for default Steam install, amend to your own Steam folder):
Arkham City
C:\Program Files (x86)\Steam\userdata\<userid>\57400\remote
Arkham Asylum
C:\Program Files (x86)\Steam\userdata\<userid>\35010\remote
3. Pick the one you want and open it in the hex editor, from the Edit menu select "Find and Replace" and into the search box put the following strings of numbers and hit search - it should find it in the file
Arkham City:
00 00 00 03 00
Arkham Asylum:
00 00 01
4. Now this should have highlighted a row of dots in the right hand column. Select
everything in that column
before the row of dots that the search highlighted, right the way to the top of the file, and delete it all. Save the file (note that tiny hexer saves a copy of the original with the extension ".bak" in case you need it).
5. Boot up the new GOTY Asylum/City and click one of the save slots to make sure a save game exists, and then exit (you don't have to actually start the game, just clicking the save slot and then exiting should be enough)
6. Now navigate to the folder with the savegames for the new version of the game, for AC it's :
Arkham City
C:\Program Files (x86)\Steam\userdata\<userid>\200260\remote
Arkham Asylum
C:\Program Files (x86)\Steam\userdata\<userid>\35140\remote
7. You should see the new save games you just created, but they won't have your GFWL user id in the save name anymore, they'll just be called "saveX.sgd" where X is the save slot number
8. Rename the file you edited with the hex-editor to remove your GFWL user id and put it into the folder in place of the one above
If all is well when you launch the game again your save should be there... Worked for me anyway!! I expect the steam app id numbers might not be identical to what I've described as it depends on which of the original game versions you had
http://www.softpedia.com/progDownload/tiny-hexer-Download-35737.html