A few notes about plans for the future of the adventure path:
Stone giants figure pretty heavily into the middle of the adventure path. The updated System Reference Document indicates that they'll probably be making an appearance in the Monster Manual 2 on May 19th. We'll see how swiftly my game progresses through The Hook Mountain Massacre, but I just did some rough math and it may arrive just in time for their appearance near the end of the adventure.
I spent a significant chunk of today going through all the old stat blocks I built for Burnt Offerings and reformatting them according to the new style I'm using. In the process I had the chance to make a lot of (mostly minor) changes to the monsters - I feel like I have a pretty good handle on monster construction at this point, but when I started doing this in July of last year I really didn't. My spring break comes up in a week, and I'll finish the rest of the reformatting then. I'll probably upload all the new stat blocks in one big go, so expect them in a couple weeks.
I'm really excited to start conversion work on Fortress of the Stone Giants, even though it's an entire adventure ahead of where my group is now. It makes me feel a little guilty, because The Hook Mountain Massacre is such a great piece too but I've found my mind jumping ahead.
I'd love to hear suggestions on what you think would make an interesting way to develop the Keeping the Keep article. I'd like to turn it into a 3-4 encounter optional side-trek but I haven't decided what direction to take it in.
I too find myself looking forward to Fortress of the Stone Giants. The adventure feels like someone used a heavy metal concept album for inspiration and I know my players are going to love it. I mean, just look at the Taiga Giant. Ho-ly crap!
When I was thinking of how to convert Keeping the Keep myself (having pulled ahead of your conversion at the time) I was thinking it would be fun to try it as some sort of massive skill check that encompasses a few smaller skill checks and combat encounters based on the scenes in the article. I never really got down to "crunching the numbers" so to speak, so I don't know how doable that really is, but the recent Dungeon articles expanding skill challenge design seem to suggest that its not impossible.
If I were going to run it as a side trek, I'd probably take a slower "day in the life" pace to it to break from the story driven heart of the adventure. Spend a few days getting to know the NPCs, find a secret passage, the next day some bandits show up, the next there's a fire, the next trouble from visiting adventures, end it with the holiday tournament deal giving them some NPCs they could possibly leave the keep to once their gone.