Like I did last time for the GSL here's a quick run down of what you can and can't do under the revised version. The short-short version is that you CAN now republish old OGL material for 4th Edition without stopping selling the other material, the whole of section 6 has been torn out and shat upon. Worldbooks still seem to be a little bit of a problem since you can't redefine races etc to suit your world, though you could use them as templates to create your own with a few tweaks. The subtle emphasis seems, still, to me to be 'we want you to create adventures' but there's room for a little more flexibility in this version.

Can Do
1. Reference material from the core rulebooks plus Player's Handbook 2, Monster Mantual 2 and Adventurer's Vault.
2. Produce RPG books and accessories in print or PDF provided they're not specifically barred.
3. You MAY reprint reference terms, tables and templates provided that they're referenced in the SRD.
4. You may come up with new terms, tables and templates of your own.
5. May use the style and content of the material covered by the SRD to create derivative works (EG Illustrations of 4th Ed material that's opened up).
6. May continue to sell under the GSL for 6 months after it is terminated, as and when this happens.
7. You MAY now convert OGL materials to 4th edition and there doesn't seem to be any restriction on publishing under both now.

Can't Do
1. May not directly copy material, unchanged, from the allowed reference books.
2. You may not define, redefine or change any of the referenced material.
3. You can't leave off the GSL logo and you can't change the size or positioning.
4. Can't leave out the block of legal text required which must appear in the first three pages.
5. Can't leave out the separate legal text from advertising.
6. No:

•     Websites.
•     Computer games/interactive projects.
•     Miniatures.
•     Character creators.
•     Character creation rules or experience rules.
•     Describing a book as a core book.
•     Refer to or use artwork or imagery from a Wiz Core book
•     Reprint any material from a core book other than already allowed.
•     Publishing material in a magazine or compilation that isn't licensed.

7. Can't reprint or republish the SRD.
8. Can't reprint definitions of 4E references from the SRD to get around this.
9. Can't reprint or reuse Wizards imagery or create derivative copies of key creatures listed in the license (EG: Illithids & Beholders).
10. Can't contain 'excessive' violence or gore.
11. Can't contain 'sexual situations',sexual abuse, pornography, gratuitous nudity, genitals or sexual activity.
12. No depicting RL groups as inferior (no bigotry or prejudice of real world groups in other words).
13. No harassment or abuse, basically no illegal content.
14. Can't refuse Wizards a copy for review, if they want one.
15. Can't directly reference page numbers.
16. Can't redefine 'fluff' - EG: rewriting a race to fit into your world background.